The founder who wanted the school closed to Muggle-born children. When the others refused, he left, but not before he built the Chamber of Secrets and sealed a basilisk inside for his heir. A thousand years later the heir is Tom Riddle, and the Chamber is opened twice. The books treat his prejudice as the house’s unfinished argument.
Appears in
On the timeline
- c. 10th century
Hogwarts is founded
Hostility in Europe pushes Godric Gryffindor, Helga Hufflepuff, Rowena Ravenclaw, and Salazar Slytherin to found a school and four houses. - Soon after the founding
The Chamber is built, and Slytherin leaves
A quarrel over who may study at Hogwarts ends with Slytherin leaving. He has already built the Chamber of Secrets and left a basilisk that only his heir is supposed to command.