Muqarnas Domes and Cornices in the Maghreb and Andalusia

Abstract

Muqarnas domes and cornices represent a unique element in Islamic architecture. Muqarnas embody a form of architectural ornament with a cellular structure. This style includes an endless variety of longitudinal friezes and, in particular, generates a system that builds astonishing vaults consisting of complex combinations of units that are challenging to distinguish. The geometric divisions of a squinch create a large number of mini-squinches that produce various Muqarnas arrangements. The Muqarnas architectural ornament can be understood by juxtaposing the different individual forms together to cover a space, creating a vault, dome or linear cornice. Here, we aim to investigate the origins of the Muqarnas cellular structure and to establish the substantial difference between the Muqarnas located in the Eastern and Western regions. Emphasis is then placed on the methodologies for assembling and building the Muqarnas in the Maghreb and Andalusia.

Introduction

This research paper describes the practice of a building method and a traditional craft called Muqarnas in Arabic and Mocárabe in Spanish, in use since the early centuries. We studied Muqarnas building practices located in the Western region of the world. We intended to provide a comprehensive investigation and to open doors for further research on the history of Muqarnas building methods with an in-depth study of its individual units. The research study required several trips, West and East, to obtain thorough results and enable contrasts. We visited Iran and Turkey in the East; North Africa, including Morocco and Cairo, for intensive investigation; and Al-Madinah City in Saudi Arabia. We also visited all the Muqarnas types in Spain and the Maghreb to obtain comprehensive results in the history of Muqarnas.

Muqarnas domes are one of the most sophisticated elements in Islamic architecture. However, few studies have been dedicated to understanding this architectural element because of its complexity, the requirement to understand various languages, and the scarcity of contextual background information. This research study highlights the Muqarnas forms located in the Western region of the World, that is, in the Maghreb and Andalusia. We provide an explanation of the individual squinch units assembling the Muqarnas to propose a hypothesis about the birth of the ingenious, architecturally ornamented Muqarnas form located in the Maghreb and Andalusia.

Interest in Europe began when James Owen (1809–1874), together with Jules Goury (1803–1834), published drawings of Alhambra Palace located in Granada (Owen and Goury 1842–1849). The publication caused a commotion; the Islamic architecture of Andalusia received considerable attention and was subsequently applied in the halls of worship in Europe, particularly in Paris and London. The delicate units forming the Muqarnas domes, cornices and architraves of Nasrid Palace in Granada represented the peak of architecture at that time, with massive propagation to other regions. With his work, Jones made the first published attempt to identify the elements that make up the Muqarnas domes of the Alhambra.¹

The Muqarnas comprise, in a deliberate way, extremely complex architectural elements that are challenging to explain in simple terms; nevertheless, they obey certain simple rules and use a limited number of pieces. The present study is an attempt to explain intricate concepts in simple terms by identifying and describing the classical Muqarnas and the composition rules that they follow. The terminology applied to Muqarnas is highly complex, although it has been greatly simplified here to allow the reader to gain an in-depth knowledge of the origins of such an ingenious constructive system in addition to its methodology of construction and assembly.

The Muqarnas consist of an infinite variety of longitudinal cornices in addition to a building method for constructing a complex dome. The Muqarnas architectural elements can be developed from various series of different units juxtaposed on others and gradually filling the space. This approach can create either a linear or a vaulted structure. Our aim is to analyse and present an in-depth study of the essential Muqarnas units used historically, and to understand their assemblies and different structural compositions.

Western Versus Eastern Muqarnas

To reach an understanding of the birth of Muqarnas, an essential study of their geographical location is important. At the one end, we have the East, where the Ottoman Empire arose: Turkey, Syria and Egypt, in addition to Iran. At the other end, we have the West, the location of Andalusia and the Maghreb. The composition rules and, in particular, the squinch units in each geographical region are highly distinctive.² Muqarnas adopt a variety of constructive forms and techniques.³ In the West, the Muqarnas are composed of small individual pieces made of wood or stucco stacked in tiers and distinguished from each other (Fig. 1). The first tier is attached to the wall and is typically formed by attaching the pieces together and then to the surface of the wall; the next tier is placed on top of the first one, and the process continues, creating successive vertical layers to form a cornice and sometimes a dome.

Fig. 1

Linear cornice of small wooden individual units in Al-Attarine Madras in Fes City, Morocco (photo: Alkadi)

In the East, during the time of the Ottoman Empire, Muqarnas were frequently made of stone or expensive marble, and the construction system was entirely different, as they were carved in horizontal ashlar courses, enabling the Muqarnas to support one another (Fig. 2). Although each Muqarnas has its own form, they are not independent pieces since they are carved on a stone ashlar of large dimensions.

Fig. 2

Ottoman Muqarnas at Architect Mimar Sinan Mausoleum in Istanbul, Turkey (photo: Alkadi)

Unlike in Maghreb and Andalusia, in the East each tier of Muqarnas is superimposed on the previous one horizontally; in some cases, they form longitudinal cornices and, in others, false vaults⁴ with varied geometric units. In both Western and Eastern Muqarnas, the design of the horizontal projection creates a template, allowing the Muqarnas of one course to coincide with those the next one.

Western and Eastern Muqarnas differ radically in their degrees of standardization. In the West, Muqarnas attain a full degree of standardization; no matter how complex a frieze or dome may be, the assembly is inevitably made up of a combination of only eight possible different pieces. Each piece has its own name, and a shape that has remained unaltered since ancient times. In contrast, in the East, the shape of the pieces can vary substantially to adapt to the intended design, although a series of unique pieces can be recognized (Fig. 3). Further, the shape of the squinch units can vary considerably to adapt to the intended design, but the pieces are still recognisable.

Fig. 3

Wooden Muqarnas of different squinch units in Fes Old City corridors, Morocco (photo: Alkadi)

Certain other essential differences can be noticed: the Muqarnas in the East, whether built in stone, brick or stucco, are aligned in horizontal planes, laid out in courses advancing on one another to form a “false” vault. The courses are coordinated for the reason of the vaulting method. However, in Western Islamic architecture, the Muqarnas design is radically different; they are made of wood or stucco and are independent vertical elements, which are glued together in vertical layers.

We note another remarkable difference between the design of Muqarnas in the East and the West: In the East, the squinches form a half-pavilion vault (Fig. 4). When this unit is divided into two, a new concave triangular Muqarnas is obtained, which is used in Western Muqarnas domes in a derivative manner.

Fig. 4

The squinch formed by a half-pavilion vault; when it is halved (right), a triangular Muqarnas appears that is fundamental in the compositions of Eastern Muqarnas (illustration: Palacios)

The spectacular result of this Oriental Muqarnas arrangement can be observed in Eastern Islamic architecture (Fig. 5). This Muqarnas results from dividing a pavilion vault by its horizontal axes. In Eastern Islamic architecture, all the Muqarnas configurations are derived from this same principle: the squinch in half-pavilion (Fig. 6).

Fig. 5

Detail of the south Iwan in Isfahan Friday Mosque, Iran, built in the thirteenth century. The Muqarnas vault is made of brick with half pavilions with openings of different angles (photo: Palacios)

Fig. 6

Fundamental differences between the Muqarnas in the East and West. On the left, the half-groin vault squinch which is the starting point of Western Muqarnas. On the right, the half-pavilion vault squinch which is the starting point of Eastern Muqarnas (illustration: Alkadi)

In contrast, in Western Islamic architecture, the essential Muqarnas is the Serwal, a quarter of the groin vault. The groin vault in Western Islamic architecture and the pavilion vault in Eastern Islamic architecture constitute the different starting points that allow us to understand, beyond their extraordinary complexity, the Muqarnas at both ends of Islam (Fig. 7).

Fig. 7

The fundamental differences between Eastern and Western Muqarnas. On the left, the half-groin vault squinch. In the centre, the triangular half-pavilion vault squinch. On the right, the square half-pavilion vault squinch (illustration: Palacios)

Origins

An explanation of the differences between Eastern and Western Muqarnas probably lies in the origin of the Muqarnas architectural element. The differences between unit forms can be observed in various historical sites. Although several hypotheses exist, most authors propose that the origin of Muqarnas lies in the space that results when turning a square plan into an octagon, that is, in the architectural element with a triangular plan that is formed when an octagonal or circular plan dome is superimposed on a square plan.⁵ This architectural problem appeared in the remote Sassanian territories where, for the first time in history, a dome was placed over a square ground plan; this must have given rise to methods were developed to solve the problem of the four triangular corners that transform the square ground plan into an octagon. This problem has been solved in various ways (Fig. 8).

Fig. 8

Squinches of early Sassanid architecture. On the left, the Firuzabad Palace conical squinch. On the right, the Sarvestan Palace half-pavilion vault squinch (photo: Palacios)

As a rule, pendentive squinches are considered minor architectural elements within an architectural complex. However, the geometric link between the octagonal or circular dome and the square ground plan dome was an extremely important architectonic invention, one in which, for example, the Roman Empire was not involved. In the Middle East, before the Islamic expansion, this problem had been solved in the dome architecture of Sassanid Persia. The conical pendentive vault, the triangular squinch, the groin or cornered vault niche were probably solutions already explored when the Arabic culture arrived in Persia.

The attraction to complexity, the exhibition of intricate geometric shapes, and the ornamentation from the meticulous fragmentation of the architectural elements are aesthetic principles of Islamic architecture. It might well be that these principles led Muslim architects to solve the problem of turning a square plan into an octagon with a half-groin vault instead of the conical squinch. The groin vault can be fragmented into two triangular plan pieces, which in turn can be combined with other pieces with a rectangular section to form more complex elements, something that the clear shape of the conical squinch does not allow at all. In this way, the technique of turning the square plan into an octagon took two divergent routes in approximately the seventh century: the Islamic, by means of the groin vault and its fragmentation in Muqarnas, and the Christian, which would clearly adopt the conical squinch.

In the third century A.D., the Sassanid discovered the conical squinch, which still exists in the remains of Firuzabad Palace (Fig. 8, left). Oddly enough, while the conical squinch was only minimally successful in Islamic architecture, it became common in the West, where, in the Romanesque period, it was a fundamental element to articulate the volumes of the transepts of Christian churches. The conical squinch remained present in the architecture of the West until the Renaissance. However, in Muslim architecture, its geometrical rotundity made it incompatible with its decorative principles, which were drawn towards infinite fragmentation.⁶

In the fifth century A.D. of the Sassanid Era, in Sarvestan Palace, the conical squinches were replaced by a new squinch formed by a half-pavilion vault (Fig. 8, right). Later, during the Islamic period in Iran, the pavilion squinch was used so frequently that it became one of the distinguishing characteristics of its architecture. In constrast, squinches were rare in the West regions, in both the Western Islamic and Christian architectures. As we will see, the half-pavilion squinch became a fundamental part in the architecture of the East, as Firuzabad and the Sassanian Empire were the impetus for this design to propagate throughout the East.⁷

Next, we have the pendentive, a spherical triangle that can be formed between the vertical walls of the cube and the lower edge of the dome. This architectural element was essential in Byzantine architecture, from which the Arabs probably learned it. In Islamic architecture, in methods for stone construction, this element is made by means of horizontal ashlar beds that, leaning on the preceding course, gradually advance over space (Fig. 9). Note that this solution allows one to decorate each horizontal ashlar bed with a succession of Muqarnas to cover the entire pendentive. In Mamelouk architecture, we can find magnificent examples of these pendentive decorated entirely with Muqarnas arranged in horizontal planes (Fig. 10).

Fig. 9

Arab squinch made by successively projecting beds (illustration: Prisse d’Avennes 1869–1877)

Fig. 10

Muqarnas squinch arranged in horizontal beds located under the dome of the central fountain in Ibn Tulun Mosque, Cairo (photo: Palacios)

Western Muqarnas

Other solutions to the squinch developed in the Western Islamic world, where the most frequent squinches are formed by half-groin vaults. The octagonal dome is placed over the square ground plan by means of a half-groin vault (Fig. 11). Whereas the origin of the half-pavilion squinch is the Sassanian Empire buildings, determining where and when the squinches of the half-groin vault originated has not yet been established, but this form is overwhelmingly present in all the Maghreb countries (Fig. 12).

Fig. 11

Dome on squinches with a half-groin vault located in Hammam Marrakech, Morocco

Fig. 12

Dome on squinches with a half-groin vault in Qarawiyyin Mosque located in Fes City, Morocco (photo: Alkadi)

The hypothesis that we propose suggests that there are three solutions to bevel a corner. These solutions are developed from three types of squinches: the half-pavilion squinch, half-groin squinch and pendentive squinch (Fig. 13).

Fig. 13

Three systems to turn the square ground plan into an octagon; from left to right: half-pavilion vault, half-groin vault and pendentive squinch (rhinoceros illustration: Palacios)

If the half-groin squinch is fragmented into two halves, we obtain a piece with a triangular plan, which is precisely the fundamental unit of the Western Muqarnas. This form unit is called Serwal⁸ in the local Moroccan language, which means “the trousers” in English (Fig. 14).

Fig. 14

The two fundamental Muqarnas: on the left, Serwal. On the right, the small pendentive named Dembouq (rhinoceros illustration: Palacios)

The next Muqarnas squinch unit is the small pendentive with a triangular plan called Dembouq, in the local Moroccan language. The plans of Serwal and Dembouq are right triangles (Fig. 14). In addition to these two units, there is a small barrel vault called T’stiya in the Moroccan local language. The face of this unit can be smooth or decorated with a small pointed arch (Fig. 15).

Fig. 15

The T’stiya, a rectangular base prism-shaped Muqarnas with its side incised in the shape of a small barrel vault with or without a lunette (rhinoceros illustration: Palacios)

The rectangular plan of this unit has a 5:7 ratio, that is, approximately the golden ratio, which gives rise to the dimensions of all the other Muqarnas squinch units. For instance, 5 is the dimension of the legs of the right triangle which the Serwal and Dembouq forms. Apart from the squinches mentioned above to develop the Muqarnas, five other squinch units were developed based on the Serwal, Dembouq and T’stiya.

Two other units are typically formed with the half-groin vault known as Chiira (in the Moroccan local language) or Jairas (in Spanish) (Fig. 16). The Chiira is formed of a rhomboidal plan. Its smallest angle measures 45°, and it is carved on a prism whose base is a right triangle base like the one that shapes the Serwal and Dembouq. As a rule, in both pieces, the central vertex projects itself considerably until it joins the bed of the lower tier of the Muqarnas.

Fig. 16

These two Muqarnas are two small groin vaults, On the left, a rhomboidal plan; on the right, a triangular plan: Chiira, or Jaira in Spanish (rhinoceros illustration: Palacios)

Additionally, we have Katif, or “shoulder”, which is a double squinch that also has a rhomboidal plan. It has a double-height piece that serves to join the courses together (Fig. 17, left). The Katif can at times be fragmented into two independent upper and lower parts. Note that a small octagonal dome is attained by grouping eight Muqarnas of this type around a vertex.

Fig. 17

On the left, Katif, a Muqarnas unit with a rhomboidal plan that goes from one level to the following; on the right, Louza, a small piece that also starts from a rhomboidal plan prism (rhinoceros illustration: Palacios)

Lastly, we have Louza, or “almond”, which has a rhomboidal plan with two cuts at its centre perpendicular to its faces, giving rise to its peculiar shape, whose shape in plan evokes an almond (Fig. 17, right).

Standardization of Muqarnas

One of the most ingenious and intelligent features of the Muqarnas system is its standardization. In the West, all decoration with Muqarnas, no matter how complex, is normally constructed with the units described above: Serwal, Dembouq, T’stiya, Chiira, Katif and Louza. The shape of each of these units always remains constant as the Muqarnas in the West are built of wood or plaster, and the prismatic sections of Muqarnas can all be obtained from the same square piece (Fig. 18). Note that the rectangular plan Muqarnas maintains the 5:7 ratio, which is a fundamental condition to achieve the matching of the adjacent pieces, since the pieces with a triangular section of leg length 5 have a hypotenuse of 7. Similarly, the pieces with rhomboidal section have a side length of 7; therefore, all of them fit perfectly to each other horizontally, tessellating the horizontal plane as if it were a tile mosaic.

Fig. 18

The eight Muqarnas are obtained from the same wooden square piece. The rectangular Muqarnas marks the dimension of the others (illustration: Palacios)

In contrast, in the Ottoman Empire and Iran, the shape of each Muqarnas is not predetermined and can vary; a triangle-plan Muqarnas can have different angles, and the same piece can be either relatively acute or, conversely, relatively obtuse. This resource, which undoubtedly allows for greater freedom of composition, is made possible in the Eastern Islamic world by the lack of a standardization system. Eastern Muqarnas, carved in stone or made of brick, are designed according to the architectural element that is desired.

The second condition for the adjoining pieces to match perfectly is verticality, which has to do with the arch in which the linking between two adjacent Muqarnas occurs: this arch must always be similar. Its curvature is determined in the rectangular Muqarnas called T’stiya, which adopts the shape of a barrel vault. The circular cut performed on that piece forms an arch in its end that must be repeated in the other Muqarnas to ensure a perfect matching of the pieces. This arch does not have a fixed design but varies from country to country: it can be pointed, round, stilted or not stilted; the shape of this small arch, however, has an important influence on the appearance of the completed work.

The Squinches

Simple squinches can be built by combining the eight Muqarnas unit reviewed above. One squinch consists of a central T’stiya, that is, the rectangular section Muqarnas with a plan proportion of 5:7, with two Serwal fitted laterally. The curvature of the central Muqarnas can be variable; its cross section, however, must be identical to that of the Serwal so that they can be assembled perfectly (Fig. 19).

Fig. 19

Simple squinch made from three Muqarnas units: a central T’stiya with Serwal on each side (rhinoceros illustration: Palacios)

We can see the same composition but with a Dembouq placed in the centre below, completing the work. The result is two-level squinch that is more complex than the previous one (Fig. 20).

Fig. 20

Two-level squinch created from the arrangement in Fig. 19 with the addition of the Dembouq (rhinoceros illustration by: Palacios)

A more complex composition with a three-level squinch is also possible. To obtain this arrangement, two Katif are added to the previous model (Fig. 21). This Muqarnas has a rhomboidal plan with the distinct characteristic of going from one level to the upper one. Between the two Katif, there is enough space to fit in one of the Serwal; on the sides, the structure can be completed with two Dembouq. The resulting composition shows an attractive complexity and movement.

Fig. 21

Three-level squinch made by added Dembouq to the example in Fig. 16 (rhinoceros illustration: Palacios)

Finally, we consider the role of Chiiras in Muqarnas compositions. Another ingenious squinch starts with two Serwal, this being a frequent way of starting all types of compositions with Muqarnas. Next, two trapezoidal Chiiras are placed in the level above, leaving enough space to place Dembouq between them. The resulting piece is a small two-level squinch, resulting into a surprising and attractive composition (Fig. 22).

Fig. 22

Two-level Muqarnas squinches with two rhomboidal plan Chiira (rhinoceros illustration: Palacios)

The Cornices

Just as the architraves of classic Greek and Roman architecture are formed with powerful horizontal bands of metopes and triglyphs, Islamic architecture is exquisitely decorated with Muqarnas cornices. It is essential to examine certain examples of simple Muqarnas cornices to understand their execution (Gonzalo and Carlos 2012). The simplest cornice composition has only two units: The Serwal and the Dembouq (Fig. 23). These are vertical prismatic pieces that are gradually laid in courses, starting with the lowest; both units fit alternately, coinciding with each other, as the contact arch is identical in both units. After the first course is completed, the following one is fixed, with a small projection, and the process continues. The result is a uniform and continuous longitudinal cornice. The building method, as it develops, advances gradually over space, generating a strong cornice or, in some cases, a barrel vault. The top part of Fig. 23 shows the upper part of this cornice, where the units join one another to completely fill the space.

Fig. 23

A simple Muqarnas frieze made with only Serwal and Dembouq (rhinoceros illustration: Palacios)

The next example is more complex. In addition to the Serwal and Dembouq used in the previous example, the rectangular plan barrel vault-shaped Muqarnas with a small pointed lunette is added (Fig. 24).

Fig. 24

A more complex muqarnas frieze made with three type of muqarnas units shown on the left side of the illustration. Starting from the right: Serwal, Dembouq and small pointed lunette (rhinoceros illustration: Palacios)

Dembouq and pointed lunettes are arranged to create small vertical towers separated from each other by the rectangular plan barrel vault-shaped Muqarnas. This design is undoubtedly more complex and dynamic than the previous ones. However, the Muslim aesthetic always aims to obtain the highest possible degree of complexity. The master builder, the Meellem, will always try to surprise us with a complex cornice executed with ingenious crystal-like Muqarnas, whole overall impression is one of small architectural motifs. These, when the fragmentation of light occurs, create attractive effects of light and shadow to arouse the curiosity and admiration of the observer. In the cornice shown in Fig. 25, four different units of Muqarnas are used. The result is one of considerable complexity and beauty. In the lower level, next to the Dembouq or small pendentive appear the Katif that make contact with the upper level. In the centre, two Chiiras are placed symmetrically, that is, small rhomboidal groin vaults create a central chapel that is ultimately completed in the upper course with two separated Katif facing each other symmetrically and separated by a small pair of Serwal placed in the centre. The third course reinforces and completes the motif initiated in the lower courses.

Fig. 25

A complex Muqarnas frieze comprising five different Muqarnas units (rhinoceros illustration: Palacios)

Muqarnas Domes in the Maghreb

Up to this point, we have focused on explaining the Muqarnas cornices. However, the building method allows us to go much further and address the construction of all types of domes, including the stalactite domes, so called due to the clusters that sometimes hang from their surface. It could be said that the construction of a Muqarnas dome rests on an essential unit: the Louza. The role of this unit is crucial to enable the courses of Muqarnas to fold over into themselves, giving rise to the mythical mthemmen, the Islamic octagon, and, with it, all types of domes (Fig. 26). As with tracery wheels in Muslim wooden structures, the presence of small octagonal domes gradually organizes the vaults and orders its surface; the other Muqarnas are then distributed ingeniously, creating varied, ever-changing arrangements that seek to surprise the observer who is sensitive to their beauty (Gonzalo and Carlos 2011).

Fig. 26

The role of the Louza is crucial to enable the courses of Muqarnas to fold over into themselves and give rise to the mythical mthemmen, the Islamic octagon, and, with it, to all types of domes (rhinoceros illustration: Palacios)

Although complex Muqarnas domes are typically made up of the eight fundamental pieces described above, sometimes, as is the case in the sophisticated Nasrid vaults of the Alhambra, certain special decorative pieces can be added. The singular dome that covers the entrance of Ben Joussef Medersa in Marrakesh (Fig. 27) was probably built during the reconstruction of the Madrasa during 1560. It is a vault built with particularly orthodox criteria and constructed exclusively from the eight fundamental Muqarnas. It begins in the corner and goes until it reaches the first small octagonal dome in the centre (Fig. 28).

Fig. 27

The Muqarnas vault over the entrance of Bin Youssef Mosque in Marrakech, built approximately halfway through the sixteenth century (photo: Alkadi)

Fig. 28

Detail of the starting point to create the Bin Youssef Muqarnas vault (photo: Alkadi)

In its lower part, the vault starts with two Serwal facing each other in the corner. On top of them lies the next course, which is formed with two triangular sections Chiiras, behind which there are two Katif and, in the centre, two more Serwal facing each other. The third course is formed with two Serwal fitted behind the Katif of the previous course; in the centre, we have two rhomboidal Chiiras. Then, the following course is formed exclusively with triangular-section Chiiras. Note that when the Chiiras are mounted on the previous course, they begin to revolve; this revolution allows the design to receive the fifth and last course, which is formed by alternating the Louza and the Serwal; with these two units, the first mthemmen is formed, that is, the small octagonal dome around which the starting point of this vault is visually organized. This first level has been reached with five vertical courses and five different Muqarnas units. In a similar way, the vault grows towards the top, creating complex patterns using the eight Muqarnas units already mentioned. Finally, the vault is closed with an octagon on the top (Fig. 29).

Fig. 29

Volumetric illustration shows the reconstruction building method of Bin Youssef Mosque Muqarnas. The illustration demonstrates the starting point of the vault (rhinoceros illustration: Palacios)

Muqarnas Domes in Spain

In the Iberian Peninsula, we find some of the most extraordinary Muqarnas domes ever created; the most remarkable ones are those in the Alhambra Palace in Granada, a building that survived under Arab culture until the end of the fifteenth century. An examination of the Muqarnas vaults and domes of the Alhambra reveals that the construction rules are exactly the same as those Eastern Muqarnas: the same units are used and are assembled using the vertical approach. Let us start by examining a curious vault located in the Infants’ Tower in the Alhambra (2006) (Fig. 30). Built with brick, the vault is relatively large for the size of a room.

Fig. 30

Brick vault forming Muqarnas with large size in the Infants’ Tower located in the Alhambra (Illustration: Palacios)

The central part consists of three groin vaults. As mentioned before, each groin vault can be split into four triangular Muqarnas, creating Serwal. Around this central part of the vault are eight triangular-plan Chiiras (Fig. 11). In this case, the Chiiras have an exceptionally long central foot, which allows for the placement of twelve Serwal units between them, thus closing the perimeter of the vault (Fig. 31). The result is simply spectacular.

Fig. 31

Illustration shows a portion of the Infants’ Tower Muqarnas vault in the Alhambra (rhinoceros illustration: Palacios)

We continue with the Hall of the Abencerrages, which is considered one of the most extraordinary Muqarnas domes in the Alhambra (Fig. 32). This design is based on the star of Islam, that is, the two squares rotated 45° with respect to one another. The room that this dome covers is square, requiring eight Muqarnas squinches to adapt the two geometric shapes. Between the dome and the squinches is a star-shaped drum with vertical walls on which sixteen windows open, their oblique light powerfully enhancing the intricate morphology of the dome, which is built entirely of stucco.

Fig. 32

The dome of the Hall of the Abencerrages the Alhambra (photo: Alkadi)

When we study the starting point of this design in detail, we again discover the eight basic Muqarnas units combined to form this structure. The building shows an extraordinary skill in the combination of the units, trying continuously to avoid monotony and repetition (Fig. 33).

Fig. 33

Detail of the dome springing in the Hall of the Abencerrages (photo: Alkadi)

The small Dembouq placed in the central corner where the dome starts has two symmetrical triangular pilasters placed on each side; these pilasters are also made up of Dembouq. Therefore, the dome starts with three supports: the central one and the two symmetrical pilasters, each of which generates its own language. In the centre, a succession of two small domes with a square plan finishes in a formidable polygonal domed structure: the eight-pointed star. This star constitutes the first visual point of the dome. On the sides, the two pilasters are crowned with two trumpet-shaped arches on which both small domes rest (Fig. 33). Except for some decorative palmettes and the trumpet-shaped arches themselves, the whole of this monumental dome complies with the compositional rigor of the Western Muqarnas.

These complex structures were probably built in workshops by means of fragmenting the complete vault design into smaller pieces so that every part could be built on the ground. Later, each of these fragments, reinforced around its perimeter with a vertical wall, would be raised and placed in its correct position. Once the dome is finished, these vertical joints allow us to identify the different fragments, since the rims of each part create on the vault a few continuous lines that delimit each sector clearly enough. Figure 34 shows a hypothetical fragmentation of the vault of the Hall of the Abencerrages into pieces, which are repeated eight or sixteen times. The completely fragmented vault is shown in Fig. 35.

Fig. 34

Group of Muqarnas units located at the base of the dome in the Hall of the Abencerrages (rhinoceros illustration: Palacios)

Fig. 35

Section of the Hall of the Abencerrages hall dome showing its fragmentation (illustration: Palacios)

Finally, we consider the vault of the Hall of the Two Sisters in the Alhambra, which is undoubtedly the most extraordinary Muqarnas construction ever created (Fig. 36). This structure is again an octagonal dome placed over a square ground plan. Four Muqarnas squinches mediate the transition from the square to the octagon. Again, a drum allows the placement of eight pairs of windows that project an oblique light over the dome’s clusters of Muqarnas. Facing each window is a small, deep dome serving to reinforce the perimeter by means of sixteen dark wells that, in turn, divide the octagonal central dome into a sixteen-pointed star-shaped vault: a broad subtle sample of the delicate nuances of Muslim geometry.

Fig. 36

The Vault in the Hall of the Two Sisters Vault in Alhambra (photo: Alkadi)

Attentive observation of the dome allows us to distinguish the joint lines of each fragment that makes up the dome (Fig. 37). The dome, in spite of its complexity, allows a remarkable simplification, since each of its parts can be fabricated comfortably in the workshop and assembled later. Each fragment is repeated eight times, except for the starting pieces over the windows, which must be executed sixteen times. Notably, only eight different fragments are required to form the cloister dome (Fig. 38).

Fig. 37

Hypothetical illustration of fragmentation of the dome of the Hall of the Two Sisters; only eight different fragments are required (Illustration: Palacios)

Fig. 38

Two fragments of the dome of the Hall of the Two Sisters, consisting of the eight Muqarnas units plus the triangular Muqarnas that make up the cloister vault (illustration: Palacios)