What are the reason for decline …

The successors of Aurangzeb were weak and became victims of the intrigues and conspiracies of the faction-ridden nobles. They were inefficient generals and incapable of suppressing revolts. The absence of a strong ruler, an efficient bureaucracy and a capable army had made the Mughal Empire weak.----------+-----+-----------------Aurangzeb failed to realise that the vast Mughal Empire depended on the willing support of the people. He lost the support of the Rajputs who had contributed greatly to the strength of the Empire. They had acted as pillars of support, but Aurangzeb’s policy turned them to bitter foes. The wars with the Sikhs, the Marathas, the Jats and the Rajputs had drained the resources of the Mughal Empire.------------:--------------The Mughals did not follow any law of succession like the law of primogeniture. Consequently, each time a ruler died, a war of succession between the brothers for the throne started. This weakened the Mughal Empire, especially after Aurangzeb. The nobles, by siding with one contender or the other, increased their own power.