The four founder of Hogwarts School of Witchcraft and Wizardry were the four greatest witches and wizards of the age. Helga Hufflepuff, Rowena Ravenclaw, Godric Gryffindor, and Salazar Slytherin. The four Houses were named after them. 

Hufflepuffs are kind people who are honest, patient, gentle, and hard-working, just like their founder. Renowned Hufflepuffs include: Ernie Macmillian, (Fighter in the battle of Hogwarts), Cedric Diggory, (Hogwarts Champion who was killed by Peter Pettigrew on Voldemort's orders), Newt Scamander, (Author of Fantastic Beasts and Where to Find Them), Nymphadora Tonks, (Auror and member of the Order of the Pheonix, killed during the Battle of Hogwarts.) 

Ravenclaws are people who value intelligence, wit, wisdom, and creativity, much like Rowena Ravenclaw. Renowned Ravenclaws include: Luna Lovegood, (Member of Dumbledore's Army and Magizoologist) Garrick Ollivander, (Famous wand maker), Sybill Trelawney (Divination Teacher at Hogwarts for many years, created the famous prophecy about Voldemort and Harry Potter), Moaning Myrtle, (First victim of the basilisk after Voldemort opened the Chamber of Secrets.)

Gryffindors are brave, chivalrous and courageous people, which are all traits of their founder. Renowned Gryffindors include: Harry Potter, (The Chosen One who killed Voldemort and was the only one known to survive the killing curse), Hermione Granger, (Current Minister of Magic), Albus Dumbledore, (Best Headmaster of Hogwarts), Neville Longbottom, (Professor of Herbology at Hogwarts and killer of Nagini, Voldemort's most prized Horcrux.)

Slytherins are ambitious, determined, and cunning people, much like Salazar Slytherin. Renowned Slytherins include: Tom Riddle, (also known as Voldemort, worst Dark Wizard ever to live), Severus Snape, (Double agent, worked for Dumbledore while he spied on Voldemort), Regulus Black, (betrayed Death-Eaters and Voldemort.)