In December 1789 , after five years of diplomatic wrangling about the terms of the Treaty of Mangalore that had ended the Second Anglo @-@ Mysore War , the ruler of Mysore Tipu Sultan again declared war on the British East India Company and their allies in Southern India . For the next two years the war continued as British forces and their allies drove the Mysore armies back towards the capital of Seringapatam . Both sides was reliant on supply by sea to maintain their campaigns inland : the British forces was supported from their major ports at Bombay and Madras , later stationing additional forces at the small port of Tellicherry inside Mysore territory . The Mysorean forces was supplied through Mangalore by French ships . France had been an ally of the Tipu Sultan 's father Hyder Ali during the Second Anglo @-@ Mysore War and although the political instability caused by the French Revolution in Europe prevented active involvement , they ensured that their ships kept up a supply of equipment to Mysore throughout the war .