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 judge ("Kazasker") was created, indicating an increasing level of social stratification between the emerging military-administrative class ("askeri") and the rest of society. Murad I also instituted the practice of appointing particular frontier warriors as "Lords of the Frontier" ("uc begleri"). Such power of appointment indicated that the Ottoman rulers were no longer merely "primus inter pares" but sat at the top of a hierarchy of leadership. As a way of openly declaring this new status, Murad became the first Ottoman ruler to adopt the title of sultan. Beginning at the latest by the 1430s, but most likely earlier, the Ottomans