The Yemeni Zaidi State, also known as the Zaidi Immamate and the Qasimid State, is a Zaidi-ruled independent state in Greater Yemen region, which is founded by al-Mansur al-Qasim in 1597 and absorbs much of the Ottoman Yemen Eyalet by 1628 and completely expels the Ottomans from Yemen by 1638.
The Zaidi state continues to exist into the eighteenth and nineteenth centuries, but gradually fractures into separate small states.
The most notable of these states is the Sultanate of Lahej; most of these states (except Lahej) submit to the Ottomans and are incorporated into the restored Ottoman province of Yemen Eyalet in 1849.