Hallmark Hall of Fame
Macbeth
20 November 1960, NBC
Role: Malcolm

Review from Los Angeles Times (PDF)

In this production, Jeremy played Malcolm, the eldest son of Duncan, the King of Scotland. In a 1981 production, JB played Macbeth, the title character and a general in the army of King Duncan.

In Shakespeare's play, Lady Macbeth plots to have her husband kill King Duncan and take the throne. The plan succeeds, and Duncan's sons, Malcolm and Donalbain, flee. More blood is spilled as Macbeth tries to thwart prophecies of the three Witches. First he kills Banquo -- whose heirs would be contenders to his throne. Upon the warning to "beware Macduff," he has everyone at Macduff's castle killed, including Macduff's wife and children. 

Macduff and Malcolm, who both have been in exile, plot to invade Scotland and overthrow the tyrant Macbeth. After more bloodshed, Malcolm ascends to the throne as the rightful new King of Scotland.

About this production, from Shakespeare in Performance: Film:

In 1960, Maurice Evans joined forces with George Schaefer to redo the 1954 Macbeth for television. This time, however, the production was first made as a movie in color. Most of it was indeed filmed on location in Scotland at considerable expense. The decision to make a film for television marked a major breakthrough in television practice. ... The expanded theatrical version was released in 1963 and made widely available on 16mm film for schools. Because the film was originally made for TV, close-ups and mid-shots tend to prevail and give it a kind of claustrophobic atmosphere, though ironically the exterior shots made on location in Scotland have been thought incongruously sunny and cheerful for a play so steeped in evil.

According to The Brettish Empire, this film of Macbeth had a premiere at the Royal Festival Hall on Dec. 9, 1960, to benefit the British Red Cross Society. "If you see a  theater credit listed for Jeremy Brett as Malcolm at the Royal Festival Hall in 1960, that's what this it -- not a play, but a screening of the film Macbeth.

IMDb page // Wikipedia page about the play // Full text of the play