Delgado worked extensively on the British stage, and on television, film and radio. His theatre debut was in 1939 and his first television appearance was 1948. He appeared in the
BBC Television serial
Quatermass II (1955), the
Powell and Pressburger wartime drama
Battle of the River Plate (1956), and came to wide popular attention in Britain when he played the duplicitous Spanish envoy Mendoza in the
ITC Entertainment series,
Sir Francis Drake, from 1961 to 1962, after which he was in much demand. Delgado was frequently cast as a villain, appearing in many British action-adventure TV series by ITC, including
Danger Man (1961),
The Saint (1962 and 1966),
The Champions (1969), and
Randall and Hopkirk (Deceased) (1969). His final radio role was in the radio sitcom
Parsley Sidings opposite
Arthur Lowe. Delgado made a total of 16 guest appearances in ITC shows, the most of any actor, with his last completed role being ITC's
The Zoo Gang (1974). He also appeared in
The Avengers (1961 and 1969),
The Power Game (1966), and an
ITV Play of the Week (
The Crossfire, 1967). His films included
The Terror of the Tongs,
The Road to Hong Kong, ''
The Mummy's Shroud and Antony and Cleopatra''. He began work as
The Master on
Doctor Who in late 1970, his first broadcast appearance being in the January 1971 adventure
Terror of the Autons. He subsequently reprised the role of the Master in the
Third Doctor serials
The Mind of Evil,
The Claws of Axos,
Colony in Space,
The Dæmons,
The Sea Devils,
The Time Monster and
Frontier in Space. An in-joke in the 1971
Doctor Who story
Colony in Space refers to his role as Mendoza in
Sir Francis Drake, when the Brigadier tells the Doctor not to worry as the suspected sighting of the Master "was only the Spanish Ambassador". The Master's story arc was to have ended in
The Final Game, which was planned as the final story to feature Pertwee's Third Doctor, but the story was scrapped following Delgado's sudden death and replaced with
Planet of the Spiders. == Personal life ==