Lucius knew Andromeda very well. The woman always was bitter towards her family and loathed everything and everyone that was dark. When she graduated, her parents wanted to marry her off to an old friend of his, Evan Rosier, who died a traitor’s death during the war, but she refused and ran away to marry a muggleborn that she had dated during her time in school. The Rosier family demanded retribution and the Blacks decided to disown her for her betrayal. With Andromeda being disowned, the Rosiers were satisfied and Severus’ brother in all but blood, Regulus Black, who was a male bearer married Evan Rosier. After the death of Evan, Regulus disappeared from the face of earth. When Narcissa checked up, he was deceased with the help of the inheritance test, but his son was still alive, who was living with Darren Rosier, Evan's older brother.