Henry Quelch was one of the form masters of Greyfriars School. He was described by William Bunter to be a "gimlet-eyed old devil." He was responsible for observing the Greyfriars students - particularly Harold Wharton, John Night, Robert Cherry, and Alexander Waverly - as potential recruits for MI5.
Quelch had a son, Quentin, who would later work for John Night's Night Industries and MI5.
Source material
Henry Quelch is a character from the Greyfriars magazine serial and (later) novel series. Quelch's role at Greyfriars is based on one of the traditional methods by which British Intelligence recruited spies–watch them from when they are young, and then recruit them before or during college.