Alexander was essentially a soldier, but he was also a serious explorer. If we compare maps of the ancient world, we gain a clear idea of the new geographical knowledge for which he was responsible. In the world picture proposed by Hecataeus of Miletus two centuries before Alexander’s time, the river Ocean wraps round a world disc with nothing much beyond Persia; a century after his death, Eratosthenes allocates nearly half the world to India, identifies the Persian Gulf, and distinguishes the Asian subcontinent from Africa.
