 The Royal Bodyguard is a British television sitcom starring an English actor best known for his portrayals of Derek "Del Boy" Trotter in what BBC comedy series? 
David Jason:  He is perhaps best known for his portrayals of Derek "Del Boy" Trotter in the BBC comedy series "Only Fools and Horses", and Detective Inspector Jack Frost in the ITV crime drama "A Touch of Frost".
i don't know