Battle of the Granicus

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 onto the defensive in the cities that remained under their control in the region.

After winning the Battle of Chaeronea in 338 BC, King Philip II of Macedon forced most of the Greek states into a military alliance, the Hellenic League. Its goal was to make war on the Persian Achaemenid Empire to avenge the second Persian invasion of Greece in 480 BC. He managed to convince the other Greek states to elect him as the leader of the League and started preparing for the war.

At the same time the Achaemenid Empire had been in crisis since the murder of its king, Artaxerxes III, in 338 BC. An important consequence of this was that Egypt again seceded from the empire. At this time there was no large Persian army in Asia Minor, and the Persian fleet was not expected in the Aegean Sea soon. Philip most likely wanted to exploit the chaos in the empire, but could not launch a large-scale invasion of Asia Minor because his entire army was not yet ready. For this reason he probably sent a smaller part of his army which could be deployed. In the spring of 336 BC he ordered a Macedonian expeditionary corps of several thousand soldiers to land on the western coast of Asia Minor. The likely mission of this advance guard was to conquer as much territory as possible, or at the very least establish a bridgehead on the Asian side of the Hellespont to facilitate the crossing of the main army later.

The advance guard was most likely led by Parmenion, Philip's best general, with Attalus as second in command. Initially the campaign was a success, with many of the Greek cities of western Asia Minor surrendering peacefully to the Macedonians. At the end of 336 BC this all changed. Philip was murdered, most likely in October 336 BC. Philip was succeeded by his son, Alexander III, who had to put down several revolts in the Balkans and Greece first to reassert Macedonian authority. This distracted him from the operations in Asia Minor. Meanwhile, Darius III had become the new Great King of the Achaemenid Empire around the autumn of 336 BC. He managed to stabilise the empire and started a counteroffensive against the Macedonian expeditionary force.

Darius prioritised the suppression of the Egyptian revolt, which probably took place from the end of 336 BC to February 335 BC. When this was done he sent Memnon of Rhodes to Asia Minor at the head of a force of Greek mercenaries, who were infantry fighting as hoplites. Memnon defeated a Macedonian force at either Magnesia ad Sipylum or Magnesia on the Maeander, probably in early spring 335 BC. Later that year another Macedonian force was defeated by a Persian army in the Troad, possibly under the command of one or more Persian satraps. By the end of 335 BC most of the Greek cities had been restored to Persian control and the expeditionary force retained only Abydus and perhaps Rhoeteum.

Once Alexander had defeated the rebellions in the Balkans and Greece, he marched his army to the Hellespont in early spring 334 BC. His army numbered around 32,000 infantry and around 5,000 cavalry. He arrived at Sestus twenty days later, where he split his army for the crossing of the Hellespont. The main part of the army was transported from Sestus to Abydus in Asia Minor, while Alexander crossed with the remainder of the infantry from Elaeus, landing near Cape Sigeum. After visiting Ilium, he passed Arisba, Percote, Lampsacus, Colonae and Hermotus.

Darius would have been informed about Alexander's movements for some time, perhaps as early as the invasion force leaving Macedon. This did not alarm the Great King yet, who left the defence of Asia Minor to his satraps there. The reasons for this may have been that Alexander had not proven himself as a commander abroad yet and that the Macedonian expeditionary force had been pushed back without much difficulty the previous year.

The Persian satraps and commanders were encamped near Zeleia with their army when they were informed of Alexander's crossing. The army was led by Arsites, the satrap of Hellespontine Phrygia; Spithridates, satrap of Lydia and Ionia; Arsames, satrap of Cilicia; Rheomithres; Petenes; Niphates and Memnon of Rhodes. While the ancient historians do not explicitly identify a commander-in-chief for the Persians, modern historians consider Arsites to have been in overall command because the enemy had invaded his territory.