He was instructed in military tactics by French officers in the employment of his father. In 1767 in the invasion of the Carnatic he commanded a corps of cavalry, and he distinguished himself in the Mahratta War of 1775-79.
At the age of 15, when he accompanied his father Hyder Ali to war against the British in the First Mysore War. He was put at the head of a large body of troops, and defeated Brathwaite on the banks of the Coleroon in February 1782.
The Second Mysore War followed five years later, and though the British were defeated this time, Tipu Sultan became convinced that the British were a new kind of threat in India. Upon becoming Sultan after his father's death in 1782, he worked to check British advances through a series of alliances. At first he attempted to secure pacts with the Marathas and the Mogul Empire.
When this failed, he turned to France, which had been a rising European power in India in decades previous, but had had their strength broken by the Seven Years' War. Expecting more from the alliance than he was to get, in 1789 he invaded the nearby state of Travancore, which was a British protectorate. This sparked the Third Mysore War, which lasted three years and resulted in a resounding defeat for Mysore. Poor timing -- France became embroiled in the French Revolution at the start of the war -- was a key factor in the loss.
Tipu Sultan's death was caused by the Fourth Mysore War. Napoleon's landing in Egypt in 1798 was intended to threaten India, and Mysore was a key to that next step. Although Horatio Nelson crushed Napoleon's ambitions at the Battle of the Nile, three armies -- one from Bombay, and two British (one of which was commanded by Arthur Wellesley the future 1st Duke of Wellington) -- nevertheless marched into Mysore in 1799 and besieged the capital, Seringapatam. On May 4th, the armies broke through the defending walls and Tipu Sultan, rushing to the breach, was shot and killed.
One notable military advance championed by Tipu Sultan was the use of mass attacks with rocket brigades in the army. The effect of these weapons on the British during the Third and Fourth Mysore Wars was sufficiently impressive to inspire William Congreve to invent Congreve rockets.
Many historians have regarded Tipu's rule as one that fostered secular and liberal views. An interesting aspect of Tipu's life was that he was a founder-member of the Jacobin Club. While accepting the membership, he declared of France thus -