Explanation:

The French assistance to Tipu Sultan in 1798 was the last instance of active intervention of any other European power in India. To counter the intrigues of Napoleon and any further development in French Power in India, Wellesley, who was extremely influenced with the imperial thoughts, came up with the scheme of eliminating the French Power from India for ever.
He placed the British on the head of the great Indian confederacy. The Fourth Anglo Mysore war had placed England on the Military supremacy in India and now Wellesley used the Subsidiary Alliance System aggressively.
It was a Treaty, between the company and the Indian native rulers. In return for a payment or subsidy, the company would place garrison troops in that ruler’s territory to fight against their rivals. An Indian ruler entering into a subsidiary alliance with the British would accept British forces within his territory and to pay for their maintenance.