All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Al-Haadawiyyah originally is a group of the Zaydiyyah groups. It belongs to Al-Haadi ila Al-Haqq (The guide to truth) Yahya ibn Al-Husayn ibn Al-Qaasim (245-298 A.H.). He got the Imaamah in Yemen and was among the people who fought the Qaraamitah in Yemen.
Allaah Knows best.