The Agrianians were crack javelinmen and the elite unit of Alexander's light infantry, who fought under the command of Attalus. They carried a bundle of javelins into battle and wore no armor, perhaps not even a shield. Alexander made heavy use of them: indeed, every time he dispatched a flying column the Agrianians were always included. They were supplied by the client king Langarus. They were expert fighters in mountainous terrain where the phalanx was obsolete. Being the elite unit of the light infantry they often took their place with the hypaspists battalion and the companion cavalry at the right wing of the army. At the battle of Gaugamela their numerical strength was 1000.

Links

Agrianians from ancientbattles.com