This historical atlas charts key aspects of the political, social and economic history of the Byzantine Empire, the dominant Mediterranean power in the fifth and sixth centuries. Surrounded by foes who posed a constant threat to its very existence, it survived because of its administration, army and the strength of its culture, of which Orthodox Christianity was a key element. This medieval empire bridged the Christian and Islamic worlds from the late Roman period through the late Middle Ages, but by the time of its demise at the hands of the Ottomans in 1453 the Byzantine empire was a shadow of its former self, restricted essentially to the city of Constantinople, modern Istanbul.