Who is General Appah Rao from Sharpe's Tiger and what is their importance?

Rao works against Tippoo even though he is supposed to be one of his generals. This is because Rao's loyalties lie with the previous ruler, who still lives. Rao wants the British to win the Battle of Seringapatam but must act as if he is on Tippoo's side. When the battle takes place, Rao orders his forces out of the city.