a long thin beard that fell almost to the bottom of his sweeping robes." According to Dumbledore, the qualities that Slytherin prized in his handpicked students included his own rare ability to speak Parseltongue, resourcefulness, and determination. He also selected his students according to cunning, ambition, and blood purity. Slytherin's first name is a reference to the mid-20th-century Portuguese dictator's surname – Rowling's 1990–1993 stay in Portugal (where memory and legacy are present long after the dictatorship era) inspired this name choice. Slytherin's background is first discussed by Professor Binns in Harry Potter and the Chamber of Secrets (and by Professor McGonagall in the film version and Professor Flitwick in the computer game). He describes the founding of the school and the schism which developed between Slytherin and the other founders, and he mentions that the castle was founded far from Muggles because, at that time, common people feared magic and persecuted suspected wizards and witches. Slytherin wanted magical learning restricted to all-magical families, as he believed Muggle-born students to be untrustworthy and he disliked teaching such students. According to ancient legend, Slytherin was responsible for the construction of the Chamber of Secrets, a chamber with contents including a Basilisk, a giant serpent that can kill by looking people directly in the eyes, susceptible to control by the Heir of Slytherin, and left there to purge the school of all Muggle-born students. Another hypothesis suggests the Basilisk was meant to fend off an invading muggle force. This occurred shortly before infighting among the four founders broke out and resulted in Slytherin's departure. Salazar Slytherin's locket, passed down to his family, was turned into a Horcrux by his descendant Voldemort and destroyed by Ron Weasley using the Sword of Gryffindor in Deathly Hallows. In June 2016, J. K. Rowling revealed on Pottermore that Slytherin's wand contained a fragment of basilisk horn, and was taught by its creator to "sleep" when instructed, which meant that it could place others who possessed the wand in a sleep from which they could only be awakened by the cries of the person's children. This secret was handed down through the centuries to each member of Slytherin's family who possessed it. By the 1600s it belonged to the Irish witch Gormlaith Gaunt, though in about 1620 it was stolen by her then-17-year-old niece Isolt Sayre, who fled to where Massachusetts, United States is today. There, she