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. It is generally believed by the historians that one of the major causes of the decline of the Mughal empire was the policy of conflict followed by Aurangzeb with the Rajput’s.
Domestic Tranquility means that there is peace, and no fighting/issues going on where you are living. It can have two different meanings though. It could also mean peace between the different states of a country. :) Hope I helped! For further details, I'd look into Google.
Adolf Hitler wrote the book "my struggle" in prison. it describes his life and his struggles as said in the title.
