Charley had been sitting quietly near her friend for the lesson so far, but decided to speak up to elaborate.
"Well, Professor, Salazar Slytherin was one of the first recorded parselmouths, also an accomplished Legilimens. He believed that only purebloods should be allowed to attend Hogwarts. That's why he left; he got into a long-standing argument with Godric Gryffindor. He also built the Chamber of Secrets. He had hoped that the monster in it-when his true heir opened it, that is-would kill all the muggleborn students. That didn't quite turn out how he'd planned, though; Harry Potter defeated the basilisk-the monster-in his....second? year at Hogwarts. 1993, I think. His locket also was made into a Horcrux by Voldemort, also destroyed, likely by Harry Potter."
Her almost boundless knowledge ran out, and she slouched back uncomfortably.