Fictional Character Appearing in the Harry Potter Book Series:

DO NOT merge with real people or into the "big tree"

"...Regulus Arcturus Black (1961 – 1979), also known as R.A.B., was a pure-blood wizard, born to Orion and Walburga Black, and the younger brother of Sirius Black. He attended Hogwarts School of Witchcraft and Wizardry in 1972 and was sorted into the Slytherin house. Regulus became a Death Eater in his youth, but defected when he found what Lord Voldemort would do in order to reach his aims. Regulus also learned about one of Voldemort's horcruxes, and decided to destroy it. He was killed in his attempt to acquire Salazar Slytherin's Locket in 1979..."

SOURCE: http://harrypotter.wikia.com/wiki/Regulus_Black