The Battle of the Granicus in May 334 BC was the first of three major battles fought between Alexander the Great of Macedon and the Persian Achaemenid Empire. The battle took place on the road from Abydus to Dascylium, at the crossing of the Granicus in the Troad region, which is now called the Biga River in Turkey. In the battle Alexander defeated the field army of the Persian satraps of Asia Minor, which defended the river crossing. After this battle, the Persians were forced on the defensive in the cities that remained under their control in the region.

Alexander III of Macedon, most commonly known as Alexander the Great, was a king of the ancient Greek kingdom of Macedon. He succeeded his father Philip II to the throne in 336 BC at the age of 20 and spent most of his ruling years conducting a lengthy military campaign throughout Western Asia, Central Asia, parts of South Asia, and Egypt. By the age of 30, he had created one of the largest empires in history, stretching from Greece to northwestern India. He was undefeated in battle and is widely considered to be one of history's greatest and most successful military commanders.