It was founded in the 10th century by Godric Gryffindor, Rowena Ravenclaw, Helga Hufflepuff and Salazar Slytherin. Each of them created a house in their names and thus established one of the best schools in the wizarding world.

How old is Gryffindor?

Given that Gryffindor would be of age by the school's founding, the latest he could be born is 976.

Who founded Gryffindor?

Godric Gryffindor

The founder of Gryffindor house. A fair man, he believed that any child who displayed magical abilities before their 11th birthday should be able to attend Hogwarts. Godric valued courage and bravery, believing these were the two most virtuous abilities a person can possess.