Hogwarts: A History
The Founding Of Hogwarts
"You all know, of course, that Hogwarts was founded over a thousand years ago - the precise date is uncertain - by the four greatest witches and wizards of the age. They built this castle together, far from prying Muggle eyes, for it was an age when magic was feared by common people, and witches and wizards suffered much persecution."
Over a thousand years ago, the four greatest witches and wizards of the age shared a dream, to create a school where young people of the Wizarding World could study and be trained in the magical arts they needed to become skilled, fully-trained Wizards. These four great Wizards each founded one of the houses of the school that they worked together to form: Hogwarts School of Witchcraft and Wizardry. They have been refered to as The Hogwarts Four.
The Founders
Godric Gryffindor
Godric Gryffindor believed that anyone who showed magical ability should be allowed to attend Hogwarts. The Sorting Hat originally belonged to Gryffindor. His sword, with rubies in the handle, has also survived and is in the possession of Dumbledore. According to the Sorting Hat, Gryffindor came from the moors. It is possible that Godric's Hollow is named after Godric Gryffindor.
(Godric's Hollow is a Muggle village where James and Lily Potter were hiding from Voldemort in October of 1981.)
Salazar Slytherin
Salazar Slytherin believed that only pure-blood Witches and Wizards should be allowed to attend Hogwarts. He got into an argument with Godric Gryffindor about this and eventually left the school. There was a legend that Slytherin built a secret chamber somewhere in Hogwarts that only his true heir would be able to open. This chamber, called The Chamber of Secrets, contained a monster that would finish his "noble purpose" of killing all the Muggle-born students at Hogwarts. As Slytherin's heir, Tom Riddle did open the Chamber and released the monster, a Basilisk. Harry Potter defeated the Basilisk with the help of Fawkes the Phoenix and the sword of Gryffindor. Slytherin was a Parseltongue. Harry Potter has many qualities Salazar Slytherin prized in his hand-picked students: Parseltongue - resourcefulness - determination - a certain disregard for rules. According to the Sorting Hat, Slytherin came from the fen.
Helga Hufflpuff
According to the Sorting Hat, Hufflepuff came from the valley. Nothing more is known about Helga Hufflepuff.
Rowena Ravenclaw
According to the Sorting Hat, Ravenclaw came from the glen. Nothing more is known about Rowena Ravenclaw.