Shakespeare’s Hamlet has always merited a footnote in astronomical histories. The setting of the play is Elsinore, the site of the fifteenth century castle greatly enlarged during the 1580s on the Öresund (Sound) between Denmark and Sweden. It is on the other end of the Baltic from Copernicus’s Frombork and not far from the Baltic island of Hven, where Tycho Brahe – a legendary Dane in his own right – built the most splendid observatory of the age. Though Hamlet speaks a few lines such as, “O God, I could be bounded in a nutshell and count myself a king of infinite space,” which could have been inspired by Bruno, Tycho is even more tangibly alluded to in the play. The names of Hamlet’s two school friends, Rosencrantz and Guildenstern, bear the names of Tycho’s ancestors as recorded on the famous portrait Tycho affixed as the frontispiece of his Astronomical Letters of 1596. I can never see Hamlet without thinking of Tycho.