Zayd ibn Ali
Zaidiyya, Zaidism or Zaydi is a Shia school named after Zayd ibn Ali. Followers of the Zaidi fiqh are called Zaidis (or occasionally Fivers). However, there is also a group called "Zaidi Wasītīs" who are Twelvers (see below). Zaidis constitute roughly 42–47% of the population of Yemen.