Battle of Granicus
The Battle of Granicus was fought between the forces of Alexander the Great and a Persian army of about 40,000 men in western Asia Minor in May 334 B.C. It was one of the early engagements in Alexander's war against Persia. Approximately half of the Persian army was made up of Greek mercenaries. Alexander led an assault across the Granicus River and was victorious in a short, sharp battle. He then liberated Asia Minor from Persian control.
Encyclopedia of Military History, Dupuy & Dupuy, 1979