What caused Third Anglo Mysore war?

Answer 1

In 1788 the company gained control of the Circar of Guntur, the southernmost of the Northern Circars, which the company had acquired under earlier agreements with the Nizam. In exchange, the company provided the Nizam with two battalions of company troops. Both of these acts placed British troops closer to Mysore, but also guaranteed the Nizam would support the British in the event of conflict.

The kingdom of Travancore had been a target of Tipu for acquisition or conquest since the end of the previous war. Indirect attempts to take over the kingdom had failed in 1788, and Archibald Campbell, the Madras president at the time, had warned Tipu that an attack on Travancore would be treated as a declaration of war on the company. The rajah of Travancore also angered Tipu by extending fortifications along the border with Mysore into territory claimed by Mysore, and by purchasing from the Dutch East India Company two forts in the Kingdom of Cochin, a state paying tribute to Tipu Sultan.

In 1789 Tipu Sultan sent forces onto the Malabar Coast to put down a rebellion. Many people fled to Travancore and Cochin, a state paying tribute to Tipu, in the wake of his advance.[5] In order to follow them, Tipu began, in the fall of 1789 to build up troops at Coimbatore in preparation for an assault on the Nedumkotta, a fortified line of defence built by Dharma Raja of Travancore to protect his domain. Cornwallis, observing this buildup, reiterated to Campbell's successor, John Holland, that an attack on Travancore should be considered a declaration of war, and met with a strong British response. Tipu, aware that Holland was not the experienced military officer that Campbell was, and that he did not have the close relationship that Campbell and Cornwallis had (both had served in North America in the American War of Independence), probably decided that this was an opportune time to attack.