Hyder Ali ruled Mysore (though he did not have the title of king).
Hyder Ali committed himself to a French alliance to seek revenge against the British.
The French declared the war against Britain in 1778.
The British East India Company began by capturing Pondicherry and other French outposts in 1778.
They then captured the French controlled port at Mahe on the Malabar coast in 1779.
Mahe was of great strategic importance to Hyder, who received French-supplied arms and munitions through the port.
Hyder formed a confederacy against the British, which, in addition to the French, included the Marathas and the Nizam of Hyderabad.
In 1780, Hyder seized Arcot.
The British then succeeded in detaching the Nizam and the Marathas from Haider and defeated him three times successively in 1781 at the battles of Porto Novo, Pollilur, and Sholinghur.
In 1782, Haider Ali inflicted a severe defeat on the English compelling them to flee Madras.
But he died shortly afterwards and the war was carried on by his son, Tipu Sultan.
Tipu Sultan continued the war for another year but absolute success eluded both the sides.
The war ended with the Treaty of Mangalore.
By this Treaty it was decided that English would return Srirangapatnam to Tipu Sultan and Tipu Sultan would handover Fort of Badnur to English.
Treaty of Mangalore—-
According to the Treaty:
By the terms of the Treaty, Tipu Sultan relinquished his claims to the Carnatic.
Tipu Sultan got back all his territories which the English had captured during the war.
The two parties were not to assist each other’s enemies directly or indirectly nor make war on each other’s allies.
The trade privileges granted to the company by Haider Ali in 1770 were to be restored although no additional benefits would accrue.
Tipu Sultan agreed to release all prisoners of war.
Tipu Sultan was to restore the factory and privileges possessed by the Company at Calicut until 1779.