"Defence Against the Dark Arts [...] was being taught at the time by an old Professor by the name of Galatea Merrythought, who had been teaching at Hogwarts for nearly fifty years."
Albus Dumbledore on his Defence Against the Dark Arts teacher[src]

Professor Galatea Merrythought was a witch and Professor of Defence Against the Dark Arts from around 1895-1945, holding the position for nearly fifty years. She worked alongside Albus Dumbledore and Horace Slughorn, her former students, but eventually retired. Some considerable time after her retirement, Tom Riddle, another one of her pupils, was refused the chance to take her place, and so jinxed the post so no wizard could hold the occupation for longer than a year. Her ultimate fate remains unknown, although, if she is still alive, she would be over 130 years old.


Early life

Nothing is known of Galatea Merrythought's past, although it is likely that she attended Hogwarts School of Witchcraft and Wizardry and would have purchased her wand from Ollivanders Wand Shop at Diagon Alley at the age of eleven. She would have graduated at the age of seventeen and it is likely that she had good Defence Against the Dark Arts marks - almost definitely a N.E.W.T. in the field.

Career at Hogwarts

Early years

"Dumbledore, in his time had access to superb teachers at Hogwarts..."
—A description of Albus Dumbledore's teachers, which included Merrythought[[src]]
Slughorn's Second office

Professor Merrythought's office

Merrythought returned to Hogwarts School of Witchcraft and Wizardry sometime around 1895 and became the Professor of Defence Against the Dark Arts, taking ownership of Classroom 3C and an office on the sixth floor. One of her pupils was a young Gryffindor named Albus Dumbledore, whom she aided in becoming an excellent duelist. Other students she taught included Elphias Doge, Aberforth Dumbledore, Horace Slughorn, Tom Riddle, and Rubeus Hagrid. The Headmaster during her early years was presumably Professor Phineas Nigellus Black, although she also went on to work under Professor Armando Dippet.

The Chamber of Secrets and retirement

"Sir? Is it true that Professor Merrythought is retiring?"
Tom Riddle questioning Horace Slughorn, the Potions Master[src]

Many years later, when Professor Dippet was Headmaster, Galatea became the teacher of a brilliant student named Tom Riddle. Her fellow colleagues, and possibly Galatea herself, had been impressed by Riddle's skills and determination, and taught him all they knew. During her fifth year of teaching Riddle, the Chamber of Secrets was opened and many of her students were petrified. Eventually, a third-year named Rubeus Hagrid was accused of releasing Slytherin's monster from the Chamber and he was expelled. It was during this year that Galatea decided to retire, whether it was because of these events or not, and she left the school following year.


  • The surname Merrythought could imply that she was adept at conjuring the Patronus, which would fit with her having taught Defence Against the Dark Arts at Hogwarts for fifty years.
  • Her given name Galatea may well be derived from Greek mythology. In Ancient Greek, the root forms would be gala(-ktos), meaning "milk", and -tea, "white". There are three notable women in Greek mythology named Galatea:
    1. Galatea of Sicily, one of the fifty Nereids (daughters of Nereus and Doris), was courted by both Polyphemus and Acis.
    2. Galatea of Cyprus was the wife of King Pygmalion. Pygmalion was famous for having created a statue of Aphrodite, the Goddess of Love, that the goddess brought to life at his request. After receiving the gift of life, Galatea married the king.
    3. Galatea was the name of the wife of King Lamprus. Galatea prayed to the Greek goddess Leto to transform her daughter into a son so she would not have to sacrifice her according to the command of her husband. Leto granted Galatea's request.

Behind the scenes

"And I'll want Professor Merrythought's old office! Not the water closet I had before!"
Horace Slughorn in Harry Potter and the Half-Blood Prince (film)[src]


Notes and references

  1. As Galatea was employed at Hogwarts around 1895, she must have been of age (17) by then.

Defence Against the Dark Arts (D.A.D.A.)
Professors: Galatea Merrythought · Quirinus Quirrell · Gilderoy Lockhart · Remus Lupin · Barty Crouch Jr. (as Alastor Moody) · Dolores Umbridge · Severus Snape ·
Amycus Carrow (as Dark Arts teacher)
Textbooks: The Dark Forces: A Guide to Self-Protection · Break with a Banshee · Gadding with Ghouls · Holidays with Hags · Travels with Trolls ·
Voyages with Vampires · Wanderings with Werewolves · Year with the Yeti · The Essential Defence Against the Dark Arts · Defensive Magical Theory · Dark Arts Defence: Basics for Beginners · Confronting the Faceless · Magical Drafts and Potions
D.A.D.A. at Hogwarts: Classroom 3C · Temporary Classroom · Hogwarts Turris Magnus · Professor's Office · Storeroom · Staircase · Lesson Cup · Race Cup · Dumbledore's Army
Spells covered under the subject: Curse of the Bogies · Knockback Jinx · Verdimillious Charm · Verdimillious Duo Spell · Verdimillious Tria · Wand-Lighting Charm · Freezing Spell · Seize and Pull Charm · Patronus Charm · Killing Curse · Cruciatus Curse · Imperius Curse · Impediment Jinx · Reductor Curse · Stunning Spell · Shield Charm · Nonverbal spells · Hex-deflection ·
Hex-Breaker · Hex Zapper
Creatures covered under the subject: Vampire bats · Iguanas · Cornish Pixies · Werewolves · Vampires · Hinkypunks · Boggarts · Red Caps · Kappas · Grindylows · Inferius