Mawgan trained at the Oxford School of Drama.
Theatre includes: Separate Tables, Bedroom Farce, Dangerous Corner (Salisbury Playhouse); An Inspector Calls, Long Day’s Journey Into Night, Twelfth Night (Octagon Bolton); Hobson’s Choice ( Octagon Bolton, New Vic, Oldham Coliseum); Faith (The Courtyard Theatre); The Beaux Stratagem (Pilot Light Theatre); Two Gentlemen of Verona (Lost Theatre); Paradise Lost (Southwark Playhouse); The Machinal (BAC); The Long Goodbye, Pericles (The New Theatre); A Month In The Country, Macbeth, Relative Values, The Rover, Larkrise to Candleford (OSD).