Conversation so far:
what are the different houses of harry potter
Hogwarts was divided into four houses: Gryffindor, Hufflepuff, Ravenclaw, and Slytherin.
who founded each of the hogwarts houses
Gryffindor was founded by Godric Gryffindor, Hufflepuff was founded by Helga Hufflepuff, Ravenclaw was founded by Rowena Ravenclaw, and Slytherin was founded by Salazar Slytherin.
who is salazar slytherin
Slytherin was one of the four founders of Hogwarts School of Witchcraft and Wizardry, regarded as one of the greatest wizards of the age, respectively as a Parselmouth.
who is godric gryffindor
Godric Gryffindor was an English wizard and one of the four founders of Hogwarts School of Witchcraft and Wizardry. He was great friends with Salazar Slytherin.

Question: why did the founders stop being friends
Self-contained rewrite: why did godric and salazar stop being friends