[1] Grant Duff was to become a civil servant of the East India Company, but being impatient at the prospect of delay in obtaining a post he accepted a cadetship in 1805 and sailed for Bombay.

During the long operations against the Peshwa Bajirao II, terminating in his overthrow, Grant Duff took a considerable part, both in a civil and in a military capacity, attaining the rank of captain in his regiment.

[3][4] Here, in the heart of a warlike province, the centre of the Mahratta confederacy, with but one European companion and a body of native infantry, he succeeded in maintaining himself in a hostile environment.

Pratap Singh the Rajah was rescued from his captivity by the Maratha Peshwa, after the Battle of Ashteh in February 1819, and restored to the throne under Grant Duff's tutelage.

He trained him so successfully in the habits of business that Pratap Singh, having improved greatly under his care,[5] was made direct ruler of Satara in 1822; but under Grant's successor, General Briggs, his behaviour was unsatisfactory.