Regulus Black was a pure-blood wizard born to Orion and Walburga Black, and the younger brother of Sirius Black. He became a Death Eater in his youth but defected when he found out what Lord Voldemort would do to reach his aims. Regulus learned about one of Voldemorts Horcruxes and decided to destroy it, which led to his death. He drank a burning potion himself rather than letting Kreacher suffer again and was dragged to his death by the Inferi. Regulus died trying to save the world, and he never took swimming lessons.