Harvey Parson

Harvey Parson (PROSE: Nothing at the End of the Lane) was the headmaster at Coal Hill School in November 1963 and, by extension, Ian Chesterton and Barbara Wright's boss. (TV: An Unearthly Child)

At that time, Parson was relatively new in the job, since Basil James Carker was Coal Hill headmaster in March 1963. (PROSE: Time and Relative)

At some point, the Imperial Daleks took control of him and used him as an undercover agent, implanting a thin device behind his ear. Upon meeting the Seventh Doctor, Parson assumed the Doctor came to apply for the job of school caretaker, and wondered if he might not be overqualified, being a doctor.

Parson was presumably killed as a security risk when the Imperial Daleks exterminated him, likely via his implant, so Mike Smith could not get information out of him. (TV: Remembrance of the Daleks)

Behind the scenes
Remembrance only gives the headmaster the name "H. Parson", but deputy headmaster Roger Kint refers to him as Harvey in Nothing at the End of the Lane.