Aeacus is the son of Zeus and Aegina. He was the monarch of the island of Aegina, which was named after his mother. When his country was depopulated by the plague, he prayed to Zeus to grant him new subjects. Zeus then provided a new population by changing ants into people. They were called the Myrmidons ("ant-people"), who later took part in the Greek expedition against Troy, led by Achilles. Aeacus was the father of the heroes Telamon and Peleus and the grandfather of Achilles.