it was, was overshadowed by subsequent events in Alexandria. In 39, Caligula performed a spectacular stunt by ordering a temporary floating bridge to be built using ships as pontoons, stretching for over two miles from the resort of Baiae to the neighbouring port of Puteoli. It was said that the bridge was to rival the Persian king Xerxes' pontoon bridge crossing of the Hellespont. Caligula, who could not swim, then proceeded to ride his favourite horse Incitatus across, wearing the breastplate of Alexander the Great. This act was in defiance of a prediction by Tiberius's soothsayer Thrasyllus of Mendes that Caligula had "no more chance of becoming emperor than of riding a horse across the Bay of Baiae". The diffusion of Greek culture and language cemented by Alexander's conquests in West Asia and North Africa served as a "precondition" for the later Roman expansion into these territories and entire basis for the Byzantine Empire, according to Errington. Letters Alexander wrote and received numerous letters, but no originals survive. A few official letters addressed to the Greek cities survive in copies inscribed in stone and the content of others is sometimes reported in historical sources. These only occasionally quote the letters and it is an open question how reliable such quotations are. Several fictitious letters, some perhaps based on actual letters, made their way into the Romance tradition. In legend Many of the legends about Alexander derive from his own lifetime, probably encouraged by Alexander himself. His court historian Callisthenes portrayed the sea in Cilicia as drawing back from him in proskynesis. Writing shortly after Alexander's death, Onesicritus invented a tryst between Alexander and Thalestris, queen of the mythical Amazons. He reportedly read this passage to his patron King Lysimachus, who had been one of Alexander's generals and who quipped, "I wonder where I was at the time." In the first centuries after Alexander's death, probably in Alexandria, a quantity of the legendary material coalesced into a text known as the Alexander Romance, later falsely ascribed to Callisthenes and therefore known as Pseudo-Callisthenes. This text underwent numerous expansions and revisions throughout Antiquity and the Middle Ages, containing many dubious stories, and was translated into numerous languages. In ancient and modern culture Alexander the Great's accomplishments and legacy have been depicted in many cultures. Alexander has figured in both high and popular culture beginning in his own era to the present day.