En Garde! Rictusempra! The Duelling Club was formed when the Chamber of Secrets was opened and Professor Gilderoy Lockhart wanted the students to learn how to protect themselves by duelling (or just get some attention for himself ). This led to one of the first scuffles between Malfoy and Potter, you know, the one where Draco conjured a snake to attack Harry. It was finally revealed to the school that Harry is a Parselmouth, which is a trait of The Heir of Slytherin.