Administration of Yemen has long been notoriously difficult.

Several dynasties emerge from the ninth to the sixteenth century, the Rasulid, which rules from 1229 to 1454, being the strongest and most prosperous.

The Ziyadid dynasty, which rules western Yemen from 819 until 1018 from the capital city of Zabid, is the first dynastic regime to wield power over the Yemeni lowland after the introduction of Islam in about 630.

The Yufirids, who hold power in the highland center of San'a and Shibam from 847 to 997, nominally acknowledge the suzerainty of the Abbasid caliphs.

The Imams of Yemen and later the Kings of Yemen, who are religiously consecrated leaders belonging to the Zaidiyyah branch of Shia Islam, establish a blend of religious and secular rule in parts of Yemen from 897.

Their imamate endures under varying circumstances throughout the period.

The Sulayhids, an Ismaili Shia dynasty established in 1047 by Ali ibn Muhammad al-Sulayhi, rules most of historical Yemen at its peak.

Affiliated to the Cairo-based Fatimid Caliphate, the Sulayhids are constant enemies of the Zaidi Shia rulers of Yemen throughout the regime’s existence to 1138.

The Najahids, a slave dynasty of Abyssinian origin, is founded in Zabid in the Tihama (lowlands) region of Yemen around 1050.

They faced hostilities from the Highlands dynasties of the time, chiefly the Sulayhids.

Their last sovereign is killed in 1158 by the Mahdids, who briefly hold power in the period between 1159 and 1174.

In spite of the name they do not represent a Shia Muslim Mahdi movement, but rather follow the Hanafi law school of Sunni Islam.

The Hamdanid sultans (the Yemeni Hamdanids) are a series of three families descended from the Arab Hamdan tribe (Banū Hamdān), who rule in northern Yemen from 1099.

The Zusayids, a Hamdani dynasty centered in Aden between 1083 and 1174, suffer the same fate as the Hamdanid sultans, the Sulaymanids and the Mahdids, since their lands are taken over by the Ayyubids, and they themselves are liquidated.

During this period, when the Fatimid state is influential, a portion of the population is converted to Ismailism.

Beginning with the conquest of Yemen by the family of Salah ad-Din ibn Ayyub (Saladin) in 1174, a series of dynasties exercises a modicum of control and administration in Yemen for roughly the next four hundred years; these are, in chronological sequence, the Ayyubids, from 1174 to 1229; the Rasulids, from 1229 to 1454; the Tahirids, from 1454 to 1517; and the Mamluks, from 1517 to 1538, when the Ottoman Empire takes the Yemeni Tihama.