Frederick Treves: Actor best known as Colonel Laytonin 'The Jewel in the Crown'

Treves as Colonel Layton with Geraldine James in ITV's lavishly produced 'The Jewel in the Crown' (1984) (ITV/REX)

A prolific screen character actor for half a century, Frederick Treves was most often seen as authorityfigures, from military types, barons and professors to doctors and headmasters. A doctor's son himself – and great-nephew of Sir Frederick Treves, the surgeon who discovered the "Elephant Man", Joseph Merrick – Treves fitted such roles like a glove, playing them in an easy, relaxed manner, with never a hint of over-acting.

His finest was Colonel Layton, commanding officer of the 1st Pankot Rifles, in ITV's sumptuous production of The Jewel in the Crown (1984), based on Paul Scott's Raj Quartet, set during the turbulent, final days of British rule in India. The character, Chillingborough-educated and patriarch of the Layton family, was the epitome of Empire – and Treves's portrayal of the "decent" British officer contrasted to great dramatic effect with Tim Piggott-Smith's as the sadistic, grammar school-educated police chief Ronald Merrick.

Later, the actor switched to comedy as the Chief of Defence Staff in Yes, Prime Minister (1986, 1987). In one episode, he was seen opposing the relocation of services personnel from the south to the north of England on the grounds that it would deprive senior officers and their wives of social events such as Wimbledon and Ascot.

Treves' background set him up well for such roles. He was born in the Cliftonville area of Margate in 1925 and educated at the Nautical College, Pangbourne, where he became head of house and chief cadet captain. From there, in 1942, he joined the Merchant Navy as a junior officer on a ship converted for wartime service that became part of an Allied convoy heading for Malta with vitally needed supplies.

Most of the ships were destroyed by German bombers and submarines and, when Treves's vessel was hit, he was blown across the deck. There were 19 survivors out of a crew of 109, and for his courage in saving an officer from drowning after jumping overboard Treves was awarded the British Empire Medal. After the war, he wrote Operation Pedestal, a play about the incident that was eventually broadcast on BBC radio in 1974.

He completed his wartime service in the Navy as a senior midshipman, then sub-lieutenant, and acted in a troops show in Sri Lanka, which inspired him to train at Rada on demob. His first professional experience was with Amersham Repertory Company. "I was there for a month but got the sack when I let the counterweight slip through my fingers," he recalled. "I nearly killed the leading lady."

Treves then found work with a company in Newquay, Cornwall, before making his West End début a year later as a Persian soldier in the TerenceRattigan play Adventure Story (St James's Theatre, 1949). There followed a season with Birmingham Repertory Company (1952-53), which performed Henry VI both at its own venue and the Old Vic Theatre, London, before appearances in The Devil's General (Savoy Theatre, 1953), The Dark is Light Enough (Aldwych Theatre, 1954), The Country Wife (Adelphi Theatre, 1956-57) and Maigret and the Lady (Strand Theatre, 1965).

Between 1978 and 1985, Treves took various roles in plays at the National Theatre, including Sir Andrew Charleson in Plenty (1978) and Manenius Agrippa, alongside Ian McKellen, in Coriolanus (1984-85), although he had to pull out after injuring his back. By then, he had established himself as one of the screen's most prolific actors, sometimes seen with a moustache but always with an ever-receding hairline, which eventually disappeared.

Following his début in the 1953B-film drama Wheel of Fate, Treves made a handful of appearances on the big screen – and was heard as a radio announcer in Carry on Constable (1960) – before television made most use of his talents. He was one of the repertory company of actors in myriad roles in The Adventures of Sir Lancelot (1956) and took one-off parts in dozens of series, including Maigret (1960), The Avengers (1967), Softly Softly (three roles, 1968, 1972, 1976) and The Liver Birds (1972). He also had short runs as the father in the BBC's 1968 adaptation of The Railway Children and Sam Lockwood (1973), an unscrupulous horse trader, in the third series of the children's drama Follyfoot.

When producers and directors needed someone with military bearing or an air of authority, Treves became one of a small band of actors on whom they regularly called. He played Colonel Cranleigh-Osborne, with the British Army in India at the start of the 20th century, throughout the second series of The Regiment (1973), the War Secretary in Ian Curteis's play Suez 1956 (1979), the all-encouraging headmaster in Stalky & Co (1982), based on Rudyard Kipling's autobiographical book about public school life, a feared brigadier in Dennis Potter's Lipstick on Your Collar (1993), Lord Quillington in To Play the King (1993), the second in the House of Cards trilogy, Colonel Richardson in The Rector's Wife (1994) and William, the autocratic father known as "The Brig", in The Cazalets (2001).

Complete with beard, Treves played Lieutenant Brotadac, a member of a band of near-human mercenaries who abduct a human, in the 1980 Doctor Who story "Meglos". He was also seen in the Len Deighton Cold War thriller Game, Set & Match (1988) as Frank Harrington, the head of the Berlin field unit who has affairs with younger women. Treves' final screen role was as a blind professor fatally taking on builders who want to develop his allotment in an episode of Rosemary & Thyme (2003).

His films included The Elephant Man (1980), in which he played an alderman trying to close down a freak show featuring the deformed Merrick, with Anthony Hopkins acting his real-life grandfather. Treves' son, Simon, is also an actor.

Frederick William Treves, actor: born Margate, Kent 29 March 1925; BEM 1943; married 1956 Margaret Stott (two sons, one daughter); died Mitcham, Surrey 30 January 2012.