Najd Sanjak an autonomous separate country within the empire. The sultan recognized Abdullah II Al-Sabah as the kaymakam of Kuwait as a subprovince of al-Ahsa, formally acknowledging that Kuwait was a part of the Ottoman Empire and that it was ruled by the Sabah family. In 1913 Ibn Saud launched an attack on Hofuf, where 1,200 Turkish troops had been stationed since the province's annexation in 1870. The Ottoman garrison was expelled from Hasa, and the territory fell to the Al Saud. Even after the conquest of Hasa, Britain considered Ibn Saud to be an Ottoman vassal, and the Anglo-Ottoman Convention of
Rise of the Ottoman Empire and vassals. When the Ottoman polity first emerged at the end of the thirteenth century under the leadership of Osman I, it had a tribal organization without a complex administrative apparatus. As Ottoman territory expanded its rulers were faced with the challenge of administering an ever-larger population. Early on the Ottomans adopted the Seljuks of Rum as models, and by 1324 were able to produce Persian-language bureaucratic documents in the Seljuk style. The early Ottoman state's expansion was fueled by the military activity of frontier warriors (), of whom the Ottoman ruler was initially merely "primus inter pares". Much of