There are a number of examples of sororicide and fratricide in adolescents, even pre-adolescents, where sibling rivalry and resulting physical aggression can get out of hand and lead to the death of one of them, particularly when a potent weapon is available or one is significantly older than the other and misjudges their own strength.
Cleopatra VII of Egypt requested the execution of her sister, Arsinoe IV, (who was guilty of treason) which was carried out under the orders of her husband, then lover, Mark Antony, in 41 BC.
Roman emperorCaligula, according to historian Suetonius, killed his sister Drusilla after learning that she was pregnant with his child in AD 38. Most historians now believe that she probably died of fever.[citation needed]
Roman emperorCommodus ordered his older sister Lucilla to be put to death in AD 182, after she was implicated in plots with members of the Senate to overthrow him.
Italian poet Isabella di Morra was killed by her brothers around 1546 for a suspected affair with a married nobleman, whom they also murdered.[1]