Yusuf Khan's military career started during the Carnatic Wars. He became a mercenary and fought alongside the French in the siege of Arcot in 1751. Robert Clive, impressed by the charges Yusuf Khan led against the battlements of Arcot, recruited him — and Yusuf Khan put his Nellore sepoys and cavalry at the disposal of the English.
Under Major Stringer Lawrence, Yusuf Khan was trained in the European method of warfare and his natural talent in military tactics and strategy blossomed to its full potential.
Over the next decade, as the Company fought the French in the Wars of the Carnatic, it was Yusuf Khan's guerrilla tactics, repeatedly cutting the French lines of supply, that did the French in, particularly during Lally's siege of Madras in 1758. Lally was to later describe the role of the Nellore Subedar's sepoys in these words: "They were like flies, no sooner beat off from one part, they came from another."
By 1760 Yusuf Khan had reached the zenith of his career as the 'all-conquering' military commandant. (A few years earlier he had been given the rank of 'Commandant of Company's sepoys'). His greatest supporter during this period was George Pigot, the English governor in Madras. Yusuf Khan was held in very high esteem even after his death by the English and in their opinion he was one of the two great military geniuses India had ever produced; the other being Hyder Ali of Mysore. Yusuf Khan was regarded for his strategy and Hyder Ali for his speed. Major General Sir. John Malcolm said of him almost a fifty years later,"Yusuf Khan was by far the bravest and ablest of all the native soldiers ever to serve the English in India".
