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A Headmaster or Headmistress (or Highmaster, in Durmstrang Institute) is the chief administrator of a School of Magic . They make all major decisions regarding the safety and the day-to-day functioning of the school, and have the power to override any decision made by any other authoritative facilitator at the school, with the possible exception of the Board of Governors (and during a brief period in 1996, the "High Inquisitor"), in Hogwarts. A Headmaster also controls the protective spells surrounding the school and the ability for certain individuals to enter or exit the grounds at will. The four founders of Hogwarts (Helga Hufflepuff , Godric Gryffindor , Salazar Slytherin , and Rowena Ravenclaw ) are not considered heads, despite leading the school during their time.

Hogwarts also has a Deputy Headmaster or Deputy Headmistress (depending on gender) that assists the headmaster in his duties. In the event of a headmaster's incapacitation, the deputy headmaster serves as temporary headmaster until the Board of Governors can elect a new, permanent one. There can also be more than one deputy headmaster, as the Carrow siblings served under Severus Snape.

Hogwarts School of Witchcraft and Wizardry

Headmasters

Known Headmasters of Hogwarts School of Witchcraft and Wizardry:

Salazar Slytherin (1003-1148)
Quintin Trimble (1148-1221)
Dexter Fortescue (1221-1315)
Phylida Spore (1315-1408)
Eoessa Sakndenberg (1408-1503)
Professor Vulpus (1503-1531)
Ambrose Swott (1531-1603)
Heliotrope Wilkins (1603-1628)
Professor Limebert (1628-1654)
Vindictus Veridian (1654-1703)
Walter Aragon (1703-1741)
Dilys Derwent (1741-1768)
Basil Fronsac (1768-1811)
Professor Everad (1811-1876)
Eupraxia Mole (1876-1884)
Phineas Nigellus Black (1884-1926)
Newton Scamander (1926-1929)^[1]
Armando Dippet (1929-1956)
Albus Dumbledore (1956-1997) (Suspended in 1993, later reinstated; assumed to have been sacked in 1996 after escaping a Ministry attempt to arrest him, reinstated later that year)
Minerva McGonagall (Acting) (1993)
Dolores Umbridge (1996) (Note: though Umbridge was proclaimed headmistress, she was not acknowledged as such by the headmaster's office, which shut her out for the remainder of the year. In addition, her portrait does not hang in the headmaster's office.)
Minerva McGonagall (Acting) (1997)
Severus Snape (1997-1998)
Minerva McGonagall (1998-2014 at least)
Galathea Kesselbrand (since 2014)