The Iliad opens with the argument between Agamemnon and Achilles. Agamemnon was the supreme commander of the Achaean army at the siege of Troy and Achilles was the finest warrior in Agamemnon's army. Both men were proud and obstinate but the blame for their dispute clearly fell on Agamemnon.chilles was the son of King Peleus and the Nereid, Thetis. His birth was the result of the union between a mortal [Peleus] and an Immortal [Thetis], which made Achilles semi-divine.