head of house
/ˌhɛd əv ˈhaʊs/originally and chiefly British
noun
1The principal of a college at the University of Oxford or Cambridge.
2The most senior pupil of a (boarding) house in a school; (also) the teacher responsible for the welfare and development of the pupils in such a house.
Origin
Late 16th century; earliest use found in Edmund Grindal (d. 1583), archbishop of York and of Canterbury. From head + of + house.