No human event had been depicted on a Greek temple previously.
The depiction of human events on the Ionic frieze of the Parthenon was a notable departure from previous Greek temple artwork. Prior to the Parthenon, Greek temple friezes typically depicted mythical or divine scenes. The Parthenon's frieze, however, depicted a procession of human figures engaged in a civic event, specifically the Panathenaic procession. This was the first time in Greek temple art that a human event was depicted, making it a significant innovation in the representation of Greek culture and history.