linguistic:paraphrasing
Zaydism is one of the three main branches of Shia Islam that emerged in the eighth century following Zayd ibn Ali‘s unsuccessful rebellion against the Umayyad Caliphate. Zaydism is typically considered to be a branch of Shia Islam that comes closest to the Sunni, although the "classical" form of Zaydism over the centuries had changed its posture with regard to Sunni and Shia traditions multiple times, to the point where interpretation of Zaydi as Shia is often based on just their acceptance of Ali as a rightful successor to prophet Muhammad. Mainstream ("twelver") Shia sometimes consider Zaydism to be a "fifth school" of Sunni Islam. Zaydis regard rationalism as more important than Quranic literalism and in the past were quite tolerant towards Sunni Shafi'ism, a religion of about half of the Yemenis. Most of the world's Zaydis are located in Northern Yemen, and in the Saudi Arabian area of Najran.