Original: He was the son of noted screenwriter and actor Roland Pertwee and cousin of actor Bill Pertwee who played Chief Warden Hodges in the comedy Dad's Army (coincidentally, Jon Pertwee was the writers' first choice for the role of Captain George Mainwaring in Dad's Army).
Simplified: He was a cousin of actor Bill Pertwee who played Chief Warden Hodges in the comedy Dad's Army.