is tragic. Part of the problem was the self-imposed isolation of the later Yemeni Kingdom, and then many years of political instability and civil war. Recently, however, a great deal of archaeology has been undertaken, and I have noticed much more about Yemen in documentaries at places like The History Channel than I have in accessible scholarly history books. Travel is now easier, despite some terrorism, and I have a friend who has inspected the ruins of the Ma'rib Dam. I trust that the archaeologists in the documentaries will eventually begin to fill in the gaps, clarify the uncertainties, and in general provide definitive histories of the area.RASSIDS, 860-1226al-Qasim al-H.asani ar-Rassid.860al-H.usaynYah.ya al-Hadi ila 'l-H.aqq897-911Muh.ammad al-Murtad.a911-913, d.922Ah.mad an-Nas.ir913-934Yah.ya934-956Yusuf al-Mans.ur al-Da'i968-998,d.1012al-Qasim al-Mansur998-1003al-H.usayn al-Mahdi1010-1013Ja'far1022-1035al-H.asan1035-1040Abu'l-Fath. al-Daylami an-Nas.ir1045-1062?S.an'a' captured by S.ulayh.ids, 1062H.amza?-1066al-Fad.il1067-1068Muh.ammad?-1085Yah.ya1117-1137'Ali1137-1138Ah.mad al-Mutawakkil1138-1171Hamdanid occupation, 1171-1174, Ayyubid occupation, 1174-1229'Abdallah al-Mans.ur1187-1217Yah.ya Najm ad-Din al-Hadi ila'l-H.aqq1217Muh.ammad 'Izz ad-Din an-Nas.ir1217-1226RasulidsAh.mad al-Mahdi al-Mut.i'1248-1258The history of Yemen under Islam, at first submerged in the triumphant Caliphates, assumes a distinctive form and enters into its own characteristic history as the result of the Shi'ite movement and the breakup of the Abbasid Caliphate. The Zaydi branch of Shi'ism held that Zayd, the brother of the Fifth Imam, al-Baqir, murdered by the Omayyad Caliph al-Hisham, was the true Imam. Zaydi doctrine, nevertheless, was that the proper Imam was not necessarily a descendant of the Prophet, but was qualified by his own personal moral and spiritual qualities. Also, they did not believe that the Imam possessed the divine spark and the intuition for authoritative doctrinal pronouncements that other Shi'ites believed was the mark of the Imam.Despite this egalitarian doctrine, the Zaydi sect in Yemen began with al-Qasim al-H.asani, who claimed descent from Ali's eldest son Hassan. During the reign of al-Ma'mun (813-833), Al-Qasim moved from Medina and established himself at S.a'da in northern Yemen. This became the center of the Zaydi Mission, whose work (for a while) was far ranging, and in time assumed secular authority in competition with other local rulers. Thus, the Imams by no means dominated Yemen. Their rule became seriously compromised when the S.ulayh.id dynasty occupied S.an'a' (which has become the modern capital of Yemen) in 1062 and then the Hamdanids in 1171. After 1258, the line of Imams continued without any political role. Nevertheless, the Imams reemerged with secular authority in the later Qasimid line. The name of his initial line, the Rassids, derived from ar-Rass in the Hijaz, is used more by Western scholars than by Yemenis.I have not given the dynasty of Hamdanids here because their predominance is brief. AYYUBIDSal-Mu'az.z.am Shams udDin Turan Shah1173-1181 d. 1186/7al-'Aziz Zahir udDin Tughtigin1181-1197Mu'izz udDin Isma'il1197-1202anNas.ir1202-1214alMu'az.z.am (alMuz.affar) Sulayman1214-1215 d. 1251/2al-Mas'ud S.alah. adDin Yusuf1215-1229Just as they might have become established, Yemen suddenly became the target again of larger political events. Forces from the powerful Ayyubid dynasty of Egypt now arrive and establish a Ayyubid collateral line as Kings of Yemen -- though the Rassids continued to hold strategic positions, including S.an'a' itself. The genealogy of the Ayyubid Kings of Yemen is given in a popup at the Ayyubid entry, but for convenience I reproduce the link