John Sudbury

Sir  was a British politician. He encountered the Third Doctor while the latter was serving as UNIT's scientific advisor. From the early 1970s (PROSE: The Eye of the Giant, The Scales of Injustice) to as late as 1989, after C19 had been cleaned up, he ran the department (PROSE: Business Unusual). Circa 1982, Sudbury asked the Fifth Doctor to investigate the disappearance of a Concorde aircraft (TV: Time-Flight). Years later, he brought in the Doctor to investigate SenéNet. (PROSE: Business Unusual)

After this incident, Sudbury officially died of a heart attack. But given that his health was excellent and his death sudden, he was probably murdered. (PROSE: Instruments of Darkness)