The Fall of Babylon: reconciling Herodotus with the historical evidence
When Babylon fell to the Persian empire in 539 BC, it was probably the most populous city in the known world. It was famous for its thick double walls that were surrounded by a moat, and the city was supposed to be able to withstand a siege for several years. Aside from the city walls there was also an additional, second line of defense, that enclosed a much larger area around the city, more than 50 kilometers on each side. The northern border of this area was the famous "Median Wall" that Xenophon reports about in his Anabasis when the ten thousand Greek mercenaries passed through the region. Only a short section of this wall has been uncovered by archaeologists, but it's clear from the ancient sources that its western endpoint stretched to somewhere beyond Sippar, while its eastern endpoint was the city of Opis. The Babylonians also built a southern wall from Babylon to Kish, and from there towards the Tigris river, but it's not known where exactly the wall intersec