The Parthenon replaced an earlier temple destroyed by the Persians.
The earlier structure is usually called the Older Parthenon or Pre-Parthenon. Construction began after the Battle of Marathon, around 490–488 BC, as a sanctuary for Athena Parthenos. It was still unfinished when Persian forces captured and sacked Athens during the second Persian invasion of Greece in 480 BC.
The Persians destroyed the Acropolis and burned the Older Parthenon along with other important religious buildings. The Athenians left much of the destruction in place for decades, and architectural fragments from the ruined temple were reused in the Acropolis fortification walls. Archaeologists later identified these remains among the so-called Persian rubble.
Pericles eventually sponsored the present Parthenon, beginning construction in 447 BC. It was built as both a replacement sanctuary and a monument celebrating Athens’s power and victory over Persia. The earlier temple is sometimes confused with the Old Temple of Athena, a separate nearby structure that was also damaged or destroyed during the Persian attack.