Coordinates: 36°50′16″N 36°12′40″E / 36.837894°N 36.211109°E / 36.837894; 36.211109

The Battle of Issus occurred in southern Anatolia, in November 333 BC. The invading troops, led by the young Alexander of Macedonia, defeated the army personally led by Darius III of Achaemenid Persia in the second great battle for primacy in Asia. After Alexander's forces successfully forced a crossing of the Hellespont (the Dardanelles) and defeated the Persian satraps led by a Greek mercenary, Memnon of Rhodes, in a prior encounter, the Battle of the Granicus, Darius took personal charge of his army, gathered a large army from the depths of the empire, and maneuvered to cut the Macedonian line of supply, requiring Alexander to countermarch his forces, setting the stage for the battle near the mouth of the Pinarus River and south of the town of Issus.

Eventual accounts tell of bodies piled within the waters high enough to dam its flow, and the river running red with blood. So while Alexander is known to have repeatedly emphasized the importance of maintaining contact with the beach to his sub-commander on the left (seaward) flank, it is safe to assume a lot of action that day along all the water course in its 2.5 km travel through the narrow and hilly coastal plain that prevented the Persians, with their greater numbers, from outflanking the attacking Greeks.