The Alexander Mosaic is a Roman floor mosaic from the House of the Faun in Pompeii. It was made in 100 BC. It shows a battle between the armies of Alexander the Great and Darius III of Persia. It measures 2.72 x 5.13m (8 ft 11in x 16 ft 9in). The original is at the Naples National Archaeological Museum. The mosaic is based on a 3rd-century BC Hellenistic painting, by Philoxenos of Eretria.