Sharpe, book 2: Sharpe's Triumph
Bernard Cornwell1998

India, 1803. Sergeant Richard Sharpe witnesses a murderous act of treachery by an English officer who has defected from the East India Company to join the Mahratta Confederation. In the hunt for the renegade Englishman, Sharpe penetrates deep into the enemy's territory where he faces temptations more subtle than he has ever dreamed of. And behind him, relentlessly stalking him is his worst enemy, the baleful, twitching Sergeant Obadiah Hakeswill who is determined to break Sharpe once and for all.

The pats of treachery all lead to the small village of Assaye where Sir Arthur Wellesley, with a tiny British army, faces the Mahratta horde. Outnumbered and outgunned, Wellesley decides to fight, and Sharpe is plunged into the white heat of a battle that will make Wellesley's reputation. It will make Sharpe's name too, but only if he can survive the carnage and killing frenzy, for it is at Assaye that he at lkast realizes his ambition and has a chance to seize it.