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
Culture of the Ottoman Empire under the Ottomans, its traditions having been shaped by the work of Abbasid calligrapher Yaqut al-Musta'simi of Baghdad, whose influence had spread across the Islamic world, al-Musta'simi himself possibly being of Anatolian origin. The Diwani script is a cursive and distinctively Ottoman style of Arabic calligraphy developed in the 16th and early 17th centuries. It was invented by Housam Roumi, reaching its greatest development under Süleyman I the Magnificent (1520–66). The highly decorative script was distinguished by its complexity of line and by the close juxtaposition of the letters within words. Other forms included the flowing, rounded Nashki script, invented