Shams al-Mo'ali Abol-hasan Ghaboos ibn Wushmgir

Qabus
Emir of the Ziyarid dynasty
Tomb of Qabus in Gonbad-e Qabus
Reign	977–981 (first reign) 997–1012 (second reign)
Predecessor	Bisutun
Successor	Manuchihr
Born	10th century
Died	1012 Gorgan
Issue	Manuchihr Iskandar
House	Ziyarid
Father	Vushmgir
Religion	Sunni Islam

Qabus ibn Wushmagir (full name: Abol-Hasan Qābūs ibn Wušmagīr ibn Ziyar Sams al-maʿālī, ابوالحسن قابوس بن وشمگیر بن زیار, شمس المعالی; (died 1012) (r. 977–981; 997–1012) was the Ziyarid ruler of Gurgan and Tabaristan in medieval Iran. His father was Vushmgir and his mother was a daughter of the Bavandi Ispahbad Sharwin II.

Upon Vushmgir's death in 967, his eldest son Bisutun marched to the capital Gurgan to take control of the Ziyarid state. A Samanid army that had arrived shortly before Vushmgir's death for a joint campaign against the Buyids, however, threw its support behind Qabus. When Bisutun gained the assistance of the Buyid Rukn al-Dawla the Samanid army left for Khurasan. Qabus found a new ally in al-Hasan ibn al-Fairuzan, who ruled in Semnan, but Bisutun occupied both Gurgan and Semnan, forcing Qabus to give up his claims as his father's successor.

Bisutun's death in 977 provided Qabus with another opportunity to take control of the Ziyarids. Bisutun's governor of Tabaristan, the Gilite Dubaj ibn Bani, supported the deceased ruler's young son, and could rely on Samanid support. Qabus gained the loyalty of the Ziyarid army, however, and received assistance from the Buyid 'Adud al-Dawla. Taking Gurgan from Dubaj, he captured Bisutun's son in Semnan. In 978 or 979 the caliph al-Ta'i granted Qabus the title Shams al-Ma'ali.

In 980 Qabus offered refuge to the Buyid ruler of Ray, Fakhr al-Dawla, who had recently fought a losing war with 'Adud al-Dawla. The latter offered the Ziyarid money and territory in exchange for the surrender of Fakhr al-Dawla, but Qabus refused. 'Adud then invaded and conquered Tabaristan; in 981 'Adud's brother Mu'ayyad al-Dawla took Gurgan. Qabus and Fakhr al-Dawla were forced to flee to Samanid Khurasan. The Samanids sent a force to take back the provinces, but were unsuccessful.