Who is Colonel Jean Gudin from Sharpe's Tiger and what is their importance?

Gudin is a French officer and military advisor to Tippoo. Gudin meets Sharpe after his capture and takes a liking to him. Gudin accepts Sharpe and Lawford into his command and talks with Sharpe about joining the French army. Later, when Sharpe is exposed as a British spy, Gudin feels disappointed but still thinks Sharpe has a good chance at a successful military career.