The Battle of Siffin was fought in 657 CE between Ali ibn Abi Talib, the fourth of the Rashidun Caliphs and the first Shia Imam, and Muawiyah ibn Abi Sufyan, the rebellious governor of Syria. The battle is named after its location, Siffin, on the banks of the Euphrates. The fighting stopped after the Syrians, faced with overwhelming odds of defeat, called for arbitration. The arbitration process ended inconclusively in 658 CE. The battle is considered a part of the First Fitna.