In 1973 he played the Duke of Buckingham in Richard Lester's "The Three Musketeers" and in 1974 appeared in its sequel "The Four Musketeers". Also in 1974 he played author-veterinarian James Herriot in the successful film adaptation of "All Creatures Great and Small". He played one of the lead roles (Lt. Crawford) in the 1976 World War I film "Aces High", then starred as Lt. William Vereker in the 1979 film "Zulu Dawn". He was also seen as Captain Hoffman, a fictional Nazi functionary, in "" (1973). Later film roles included Zor-El in "Supergirl" (1984).