Naples National Archaeological Museum
The Alexander Mosaic, a floor mosaic dating from c. 100 BC, is believed to be a "reasonably faithful" copy of "Battle of Issus", though an alternative view holds it might instead be a copy of a work painted by Apelles of Kos, who produced several portraits of Alexander the Great. It measures , and consists of approximately 1.5 million tesserae (coloured tiles), each about square. The mosaicist is unknown. Since the mosaic was not rediscovered until 1831, during excavations of Pompeii's House of the Faun, Altdorfer could never have seen it. It was later moved to the Naples National Archaeological Museum in Naples, Italy, where it currently resides.