4 ideas
The Mughals had no fixed rule of succession: under Timurid custom every son of the emperor had an equal claim, so the throne went to whichever prince could win it by force. Each succession therefore became a war of elimination among brothers. Princes spent their fathers' reigns building armies and alliances among the nobles, and often rebelled before the father died.
Akbar ranked every noble by a numerical mansab. The rank set both his personal status and the number of cavalry he had to keep. He was paid through jagirs, grants of land revenue that were regularly transferred, and his estate reverted to the crown at death. The same design encouraged them to extract as much as they could in the short term.
Shah Jahan fell ill in 1657, and his four sons fought for the throne. Aurangzeb defeated his eldest brother, Dara Shikoh, at Samugarh in 1658, and later had him paraded through Delhi and executed. He also eliminated his other brothers, Shuja and Murad. He then kept his father, Shah Jahan, confined in the Agra fort until Shah Jahan died in 1666.
Conquest enlarged the territory to be administered but did not bring in matching revenue. Jagirs grew scarce while the number of mansabdars grew, the Rajput alliance was alienated by religious policy, and the heartland was left to governors. The empire was at its largest when he died in 1707, and it broke apart soon after.