Thaïs (Greek: Θαΐς) was a famous Greek hetaera who lived during the time of Alexander the Great and accompanied him on his campaigns. She is most famous for instigating the burning of Persepolis. At the time, Thaïs was the lover of Ptolemy I Soter, one of Alexander's generals. It has been suggested that she may also have been Alexander's lover, on the basis of Athenaeus's statement that Alexander liked to "keep Thais with him", but this may simply mean he enjoyed her company. She is said to have been very witty and entertaining. Athenaeus also says that after Alexander's death Ptolemy married Thaïs, who bore him three children.
Thaïs apparently came from Athens and accompanied Alexander throughout his campaign in Asia Minor. She came to the attention of history when, in 330 BC, Alexander burned down the palace of Persepolis, the principal residence of the defeated Achaemenid dynasty, after a drinking party. Thaïs was present at the party and gave a speech which convinced Alexander to burn the palace. Cleitarchus claims that the destruction was a whim; Plutarch and Diodorus recount that it was intended as retribution for Xerxes' burning of the old Temple of Athena on the Acropolis in Athens (the site on the extant Parthenon) in 480 BC during the Persian Wars.
When the king [Alexander] had caught fire at their words, all leaped up from their couches and passed the word along to form a victory procession in honour of Dionysus. Promptly many torches were gathered. Female musicians were present at the banquet, so the king led them all out for the comus to the sound of voices and flutes and pipes, Thaïs the courtesan leading the whole performance. She was the first, after the king, to hurl her blazing torch into the palace. As the others all did the same, immediately the entire palace area was consumed, so great was the conflagration. It was remarkable that the impious act of Xerxes, king of the Persians, against the acropolis at Athens should have been repaid in kind after many years by one woman, a citizen of the land which had suffered it, and in sport.