The Granicus River in Turkey is seen, where Alexander the Great’s army first fought the Persian Empire. Stone carvings of Alexander on his horse, Bucephalus, and other soldiers and mounted warriors. Map of Alexander’s progression from Macedonia into Asia Minor. The Persian King Darius was forced to assemble a large army at the Issus River to meet Alexander. A mosaic of Alexander and his army facing Darius and the Persians. Darius ended up defeated.