The Hashemites (al-Hāshimiyyūn), also House of Hashim, are the royal family of Jordan, which they have ruled since 1921, and were the royal family of the kingdoms of Hejaz (1916–1925), Syria (1920), and Iraq (1921–1958). The family had ruled the city of Mecca continuously from the 10th century, frequently as vassals of outside powers, and were given the thrones of the Hejaz, Syria, Iraq, and Jordan following their World War I alliance with the British Empire; this arrangement became known as the "Sharifian solution". The family belongs to the Dhawu Awn, one of the branches of the Ḥasanid Sharifs of Mecca, also referred to as Hashemites. Their eponymous ancestor is traditionally considered to be Hashim ibn Abd Manaf, great-grandfather of the Islamic prophet Muhammad. The Ḥasanid Sharifs of Mecca (from whom the Hashemite royal family is directly descended), including the Hashemites' ancestor Qatadah ibn Idris, were Zaydī Shīʿas until the late Mamluk or early Ottoman period, when they became followers of the Shāfiʿī school of Sunnī Islam. The current dynasty was founded by Sharif Hussein ibn Ali, who was appointed as Sharif and Emir of Mecca by the Ottoman sultan Abdul Hamid II in 1908, then in 1916—after concluding a secret agreement with the British Empire—was proclaimed King of Arab countries (but only recognized as King of the Hejaz) after initiating the Arab Revolt against the Ottoman Empire. His sons Abdullah and Faisal assumed the thrones of Jordan and Iraq in 1921, and his first son Ali succeeded him in the Hejaz in 1924. Abdullah was assassinated in 1951, but his descendants continue to rule Jordan today. The other two branches of the dynasty did not survive; Ali was ousted by Ibn Saud after the British withdrew their support from Hussein in 1924–1925, and Faisal's grandson Faisal II was executed in the 1958 Iraqi coup d'état. According to historians Ibn Khaldun and Ibn Hazm, in 968 Ja'far ibn Muhammad al-Hasani came from Medina and conquered Mecca in the name of the Fatimid caliph al-Mu'izz after the latter had conquered Egypt from the Ikhshidids.