Brutus was probably born in 85 b.c. of a consciously tyrannicidal family, which claimed descent on the father's side from L. Junius Brutus (who overthrew the Tarquins in 509 b.c.) and on the mother's, from C. Servilius Ahala (who slew the aspiring dictator Spurius Maelius in 439 b.c.). These claims seem fanciful: the family cannot with certainty be traced back beyond the late fourth century b.c. After Pompey the Great's treacherous slaughter of Brutus's father in 77 b.c., Brutus was adopted by his maternal uncle, Q. Servilius Caepio, and hence was often referred to as Caepio Brutus.