Lord Serpentine

Edmund Salazar Slytherin, later known as Lord Serpentine (b. 990) was an English-Irish Pure-Blood Wizard and Dark Lord who was the son of Hogwarts Founders, Salazar Slytherin.

After the death of his mother and massacre of her murderers at the hands of his father, Edmund left Hogwarts with his father and brother after killing his cousin, Godwin Gryffindor in a duel. Salazar disowned his son, so Edmund travelled the world, learning everything he could about the Dark Arts before returning to England and forming the Sons of the Serpents, a Dark Arts cult. Edmund renamed himself Lord Serpentine and attempted to take over England in the aim of reshaping the world in a Pure-Blood paradise.

However, the Fellowship of the Lion thwarted his plans and Edmund was eventually killed by his uncle and the fellowships leader, Godric Gryffindor.