After his conquest of Persia, Alexander led his armies thousands of miles across unknown terrain, in search of the eastern boundary of the world. Even at the time of his death he did not know the extent of the land which he ruled, and Asia remained a mystery to Westerners for centuries, until the great age of exploration and the development of printing in the fifteenth century AD. This map of the Mediterranean World--the world that Alexander conquered--was produced by a Dutch cartographer, Abraham Ortelius, in 1579.