This broken relief shows grooms carrying saddle-cloths and whips. It was discovered decorating the Apadana, or audience hall, in the Persian centre of Persepolis. This hall had relief sculpture on the north and east sides. Each side was a mirror image of the other, but the north side, from which this relief came, has been exposed to the elements for centuries and is now in a poor condition. Towards the end of the reign of the Persian king Cambyses (530-522 BC) a revolt broke out. On his way to deal with the problem, Cambyses was accidentally killed. The rebellion was eventually crushed by a group of seven conspirators and one of them, Darius, became the next king. He was keen to stress his legitimacy and founded Persepolis as a new royal centre. His successors, Xerxes, Artaxerxes I and Artaxerxes III, continued to build at Persepolis. The most important buildings, including the Apadana, were built on a terrace of natural rock which rose above the surrounding plain. Although, following Assyrian tradition, much use was made of stone decoration, many walls would originally have been made of mud brick, which has now disappeared. Persepolis was destroyed by Alexander the Great in 330 BC.