At the time, when Nadir Shah attacked Delhi, the Mughal Emperor was

At the Battle of Karnal on 24 February 1739, Nader led his army to victory over the Mughals. Muhammad Shah surrendered and both entered Delhi together. The keys to the capital of Delhi were surrendered to Nader. He entered the city on 20 March 1739 and occupied Shah Jehan's imperial suite in the Red Fort.