Answer
In the Kingsman film franchise, Colin Firth portrays the character of Harry Hart, a veteran secret agent also known by his codename "Galahad". He serves as a mentor and trainer to the protagonist, Gary "Eggsy" Unwin, guiding him in the world of espionage and covert operations. Firth's portrayal of Harry Hart is characterized by a combination of wit, sophistication, and physical prowess, making him a captivating figure throughout the series.