Matricide's the act of killing one's mother. As for any type of killing, motives can vary a great deal. Known or suspected matricides Amastris, queen of Heraclea, was drowned by her two sons in 284 BC. Cleopatra III of Egypt was assassinated in 101 BC by order of her son, Ptolemy X, for her conspiring. Ptolemy XI of Egypt had his wife, Berenice III, murdered shortly after their wedding in 80 BC. She was also his stepmother, or perhaps his mother. In AD 59, the Roman Emperor Nero's said… (More on Matricide)