Muhammad ibn Abi Bakr
After the Battle of Siffin, Ali ibn Abi Talib appointed Muhammad ibn Abi Bakr as the Governor of Egypt, then a newly conquered province of the Islamic empire. In 658 CE (38 AH), Mu'awiya ibn Abi Sufyan, the then Governor of Syria, sent his general Amr ibn al-As and six thousand soldiers against Muhammad ibn Abi Bakr. He hadn't proved himself to be a good governor, Lazley Hazleton writes "Muhammad AbuBakr – Aisha's half brother – had proved a weak governor. Ali himself ruefully acknowledged that he was "an inexperienced young man". Muhammad asked Imam Ali for help. Ali is said to have instructed his foster son to hand the governorship over to his best general and childhood friend, Malik al-Ashtar, whom he judged better capable of resisting Amr ibn al-As. However, Malik died on his way to Egypt. The Shi'a and Institute for Shia Ismaili Studies and London's Shi'aism researcher Wilferd Madelung believe that Malik was poisoned by Muawiyah I.