Simplify the following text for a Grade 3 native English-speaking person.
Original: Peleus was the son of Aeacus , king of the island of Aegina , and EndeÃ s , the oread of Mount Pelion in Thessaly ; he was the father of Achilles .
Simplified: Peleus was one of the famous early Greek heroes . He was the son of Aeacus , King of Aegina .