He extended Mogul power, notably in the Deccan, and rebuilt the capital at Delhi. His buildings there and in Agra, notably the Taj Mahal, built as a shrine for his wife, mark the peak of Indo-Muslim architecture. His severe illness in 1657 caused a succession war between his four sons in which Aurangzeb, the third son, killed his rivals, imprisoned his father in the Agra palace, and seized the throne. On his death Shah Jahan was buried with his wife in the Taj Mahal.