His other notable film appearances included The Hill (1965), Repulsion (also 1965), Doppelgänger (1969), Tales from The Crypt (1972), Theatre of Blood (1973), and The Passenger (1975).

In 1949, he began his National Service as part of the programme of conscription in the United Kingdom introduced after World War II.

He spent two years with the 32nd Medium Regiment, Royal Artillery, during which time he paced for Christopher Chataway in athletics and ran a motorcycle stunt team.

[citation needed] Hendry's professional acting career began in 1955, working in repertory at the Hornchurch Theatre in Station Lane.

However, production of the first season was curtailed by a strike and Hendry used the opportunity to depart the series and begin a film career – The Avengers continued with Macnee as its lead.

[7] Hendry had lead roles in several films; Live Now, Pay Later (1962), Girl in the Headlines (1963), This is My Street (1964),[8] The Hill (1965) opposite Sean Connery, and Roman Polanski's Repulsion (1965).

[9] In the early 1970s, Hendry had lead roles in several TV series including The Adventures of Don Quick (1970) and The Lotus Eaters (1972–73).

He guest starred, alongside Brian Blessed, in the first episode of The Sweeney, titled "Ringer", made in 1974 and broadcast early in 1975.

He appeared regularly as a guest star in TV series including The Persuaders!, Dial M for Murder, Churchill's People, Thriller, Van der Valk, Supernatural, Crown Court, The Enigma Files, Bergerac and The Chinese Detective.

Towards the end of the decade Hendry appeared as a former SAS Trooper and convict Roy Gates in the Return of the Saint episode "Yesterday's Hero.

Among the more widely seen films he appeared in during this time were Get Carter (1971), for which he received a BAFTA nomination for Best Supporting Actor, Theatre of Blood (1973) opposite Vincent Price, The Passenger (1975) and Damien - Omen II (1978).

[citation needed] Hendry starred opposite Nyree Dawn Porter in the TV series For Maddie with Love (1980).

Towards the end of his life he had a role in the crime series Jemima Shore Investigates as the eponymous heroine's literary agent.