Gryffindor

Said to be one of "the four most brilliant witches and wizards of the time",[4] Godric Gryffindor founded Hogwarts School of Witchcraft and Wizardry in his adulthood, with friends Salazar Slytherin, Helga Hufflepuff, and Rowena Ravenclaw, though he later severed ties with Slytherin. He even appeared to have carefully selected members of his own House.

Gryffindor was said to have praised courage, determination, and strength of heart above all other qualities. Indeed, he selected students for his house based upon their daring and bravery, according to the Sorting Hat. He also was the most in favour of allowing Muggle-borns into the school.

The founders, however, were unsure of how they would sort the students when they were dead. To solve this, Gryffindor took off his hat and all four of them enchanted it so that it could sort the students long after their deaths. It was, from then on, known as the Sorting Hat.

Gryffindor was initially a close friend of Salazar Slytherin, but over time their friendship deteriorated. After a number of years of working peacefully together, Slytherin eventually grew apart from his fellow founders due to his distrust of Muggle-borns, and his belief that they should not be accepted into Hogwarts. When Slytherin failed to convince Gryffindor and the others to accept his ideas, he chose to leave the school. Unbeknownst to Gryffindor, his former friend built a hidden chamber within the castle, in which he hid a basilisk that his heir would later use to try and purge the school of Muggle-borns.

It is unknown how or when Gryffindor died, though he left an enduring legacy.

Source of information: https://harrypotter.fandom.com/wiki/Godric_Gryffindor