The Hamdanid dynasty (Arabic: حمدانيون, romanized: Ḥamdānyūn) was a Shia Muslim Arab dynasty of northern Mesopotamia and Syria (890–1004). They descended from the ancient Banu Taghlib Christian tribe of Mesopotamia and Eastern Arabia.
The Hamdanid dynasty was founded by Hamdan ibn Hamdun. By 892-893 he was in possession of Mardin, after fighting the Kharidijis of Djazira. In 895 Caliph al-Mutadid invaded, and Hamdan fled Mardin.
Hamdan's son Husayn, who was at Ardumusht, join the caliph's forces. Hamdan later surrendered to the caliph and was imprisoned. In December 908, Husayn conspired to establish Ibn al-Mu'tazz as Caliph. Having failed, Husayn fled until he asked for mediation through his brother Ibrahim. Upon his return he was made governor of Diyar Rabi'a. In 916, Husayn, due to a disagreement with vizier Ali b. Isa, revolted, was captured, imprisoned, and executed in 918.
Hamdan's other son, Abdallah, was made governor of Mosul in 905-906. He conducted campaigns against the Kurds in that region and in 913-914 was dismissed from his post and subsequently revolted. Abdallah submitted himself to Mu'nis, and with his pardon was made governor of Mosul in 914-915. During his brother Husayn's revolt, both he and his brother Ibrahim were temporarily imprisoned. By 919, Abdallah was commanding an army against Yusuf b. Abi l'Sadj, governor of Adharbaydjan and Armenia.
His lineage still ruled in Mosul, a heavy defeat by the Buyids in 979 notwithstanding, until 990. After this, their area of control in northern Iraq was divided between the Uqaylids and the Marwanids.
Ali Sayf al-Dawla 'Sword of the State' ruled (945–967) northern Syria from Aleppo, and became the most important opponent of the Christian Byzantine Empire's re-expansion. His court was a centre of culture, thanks to its nurturing of Arabic literature, but it lost this status after the Byzantine conquest of Aleppo.