In 1657 Shahjahan fell ill, precipitating a struggle for succession between his four sons, Dara Shikoh, Murad Baksh, Shah Shuja, and Aurangzeb. The victor, Aurangzeb, declared himself emperor in 1658 and strictly confined Shah Jahān in Agra Fort until his death. There was no codified Law of Succession for the Mughal dynasty.