Every fourth year the ordinary Panathenaea gave way to the Great Panathenaea, an expanded version of the same festival with grander competitions, larger prizes and, most visibly, a much larger peplos, grown by the Classical period from a garment a person could carry to a rigged sail hauled through the city on the mast of a wheeled processional ship. The scale of the Great Panathenaea, and Athens' evident interest in publicizing it, is part of why many historians read the festival as functioning as civic ritual and diplomacy at once, an occasion to display Athenian wealth and religious devotion to visitors from the wider Greek world and, later, from cities within the Athenian empire that sent representatives and offerings as a mark of their standing relative to the city.
The frieze that once ran around the Parthenon's inner colonnade is widely, though not universally, read by archaeologists as depicting this procession, ending in a scene showing a folded cloth passed between human and divine hands, and if that reading is correct, then the temple raised for the newer, gold and ivory statue of Athena Parthenos also carried a permanent record of the older festival owed to her more ancient cult image. The Panathenaea continued, in some diminished form, well into the Roman period, one of the longest continuously attested civic festivals of the ancient Greek world.