Alavids

The Alavids or Alavians or Alids or Alijds, also known as the Zaydids, were a Zaidi Shia emirate based in Mazandaran (Tabaristan). They were descendants of the second Shi'a Imam (Imam Hasan ibn Ali) and brought Islam to the south Caspian Sea region of Tabaristan. Their reign was ended when they were defeated by the Samanid empire in 928 AD. After their defeat some of the soldiers and generals of the Alavids joined the Samanid dynasty. Mardavij the son of Ziar was one of the generals that joined the Samanids. He later founded the Ziyarid dynasty. Ali, Hassan and Ahmad the sons of Buye (that were founders of the Buyid or Buwayhid dynasty) were also among generals of the Alavid dynasty who joined the Samanid army. Their capital was the city of Amol.