The Buchis bull was one of several sacred bulls, the most famous being the Apis bull at Memphis. Bulls were symbolic of physical strength and were associated with male fertility. The Buchis bull was sacred to Montu, and lived at Armant, south of Thebes. Like the Apis, there was only one Buchis bull at a time. He was identified by special markings, a white body and black face. Macrobius, a Roman writer living in about AD 400, records the unlikely information that the bulls changed colour hourly, and had hair which grew backwards. When it died, the Buchis bull was mummified and placed in a catacomb known as the Bucheum. Each burial was marked by one or more stelae, just like those put up for human tombs. This one shows the king offering bread to the bull, who stands behind an offering table laden with the food to sustain him through eternity. The information on these stelae helped Sir Robert Mond and Walter Bryan Emery to determine the dates of the burials, when they discovered the Bucheum in 1927. The catacombs that they found were used from the time of Nectanebo II (reigned 360-343 BC) to that of Diocletian (AD 284-305), a period of over 600 years.