Simplify the following text for a Grade 7 native English-speaking person.
Original: The History of the Peloponnesian War is an account of the Peloponnesian War in Ancient Greece , fought between the Peloponnesian League ( led by Sparta ) and the Delian League ( led by Athens ) .
Simplified: The History of the Peloponnesian War tells the story of the Peloponnesian War in Ancient Greece .