Salazar Slytherin was one of the four legendary founders of Hogwarts School of Witchcraft and Wizardry in the 10th century. A powerful wizard and a famous Parselmouth, he was the founder of Slytherin house, which values ambition, cunning, leadership, and resourcefulness. His staunch belief that magical education should be reserved for pure-blood wizards and witches led to an irreparable conflict with the other founders, particularly Godric Gryffindor. Slytherin's most significant legacy is the clandestine Chamber of Secrets he built within Hogwarts, and his lineage, which ultimately produced his final heir, Lord Voldemort.
Alongside Godric Gryffindor, Helga Hufflepuff, and Rowena Ravenclaw, Salazar Slytherin co-founded Hogwarts with the shared goal of creating the world's finest magical school. For a time, the four worked in harmony, each selecting students for their respective houses based on desired qualities. Slytherin favored students who were ambitious, shrewd, and from pure-blood lineages. His insistence on a pure-blood-only admission policy became a major point of contention. Slytherin argued that Muggle-born students were untrustworthy and unworthy of learning magic. This ideology clashed fiercely with the more egalitarian views of the other founders, especially his once-close friend, Godric Gryffindor. The disagreement escalated into a serious argument, culminating in Slytherin's decision to leave the school he had helped build. Before departing, Slytherin secretly constructed the Chamber of Secrets deep within the castle. According to legend, as told by Professor Binns, Slytherin sealed the Chamber, ensuring that only his true heir could open it. The heir would then be able to unleash the monster within—a Basilisk—to purge the school of all students Slytherin considered unworthy to study magic. This dark legacy haunted Hogwarts for centuries, becoming a reality when his descendant, Tom Marvolo Riddle, opened the Chamber twice.
Salazar Slytherin's physical appearance is known primarily from the colossal statue of him in the Chamber of Secrets. The statue depicted him as an ancient and “monkeyish” man with a long, thin white beard that flowed down to the bottom of his sweeping stone robes. As described by the Sorting Hat, Slytherin was “power-hungry” and “shrewd.” His defining personality traits were immense ambition and a strong sense of pride, particularly concerning blood purity. He was cunning, determined, and resourceful, qualities he valued in his students. However, his prejudice against Muggle-borns reveals a deep-seated intolerance and elitism. His willingness to build the Chamber of Secrets and leave behind a murderous beast demonstrates a profound capacity for ruthlessness and a desire to see his dark ideals perpetuated long after his death.