More than 100 years after Akabar's death, the Mughal Empire began to fall apart. What were two of the reasons that caused this to happen?

One is that his empire was left in hands of his sons who weren't such good rulers as Akabar was. This lead to a lot of internal problems with politics, government, and economy. In effect this means that the Mughal Empire was weakened within.

The second reason came from outside - knowing that the Mughal Empire was weakened following Akabal's death, Nadir Shah, the ruler of Persia in those times, decided to attack the empire and take control over it.