The Zaidiyyah () are a Shia Muslim sect. They are different from the usual Shia Islam. This is because of the argument over the who the 5th Imam, or religious leader, is. They believe the 5th Imam was Zaid ibn Ali while usual Shia Muslims believe that his brother, Muhammad, was the 5th Imam. Zaydi Muslims also follow a long list of other imams after imam Zayd Bin Ali. Zaydi Muslims believe the imam isn't appointed by God, unlike other Shia Muslims. Other ways Zaydis are different from other Shia Muslims include prohibition of mutah, not doing taqleed, and believing imams can make mistakes and should be overthrown if they do.