a semi-independent prince until his eventual assassination. Indeed, Merv operated as the centre of Abbasid partisanship for the duration of the Abbasid Revolution of 746–750, and became a consistent source of political support for the Abbasid rulers in Baghdad later on; the governorship of Khurasan at Merv was one of the most important political figures of the Caliphate. The influential Barmakid family, based in Merv, played an important part in transferring Greek knowledge (established in Merv since the days of the Seleucids and Greco-Bactrians) into the Arab world. Throughout the Abbasid era, Merv remained the capital and most important city of Khurasan. During this time, the Arab historian Al-Muqaddasi (c. 945/946–991) called Merv "delightful, fine, elegant, brilliant, extensive, and pleasant". Merv's architecture inspired the Abbasid re-planning of Baghdad. A 10th-century Arab historian, Ibn Hawqal, wrote of Merv: "and in no other city are to be seen such palaces and groves, and gardens and streams". Merv was also known for its high-quality textiles. A 12th-century Arab geographer al-Idrisi noted: "From this country is derived much silk as well as cotton of a superior quality under the name of Merv cotton, which is extremely soft." The Islamic world admired the elegant robes and silk turbans produced in Merv. The city was notable as a home for immigrants from the Arab lands and those from Sogdia and elsewhere in Central Asia. In the period from 813 to 818, the temporary residency of the caliph, al-Ma'mun effectively made Merv the capital of the Muslim world and highlighted Merv's importance to the Abbasids. A descendant of the Islamic prophet Muhammad, 8th Imam of Twelver Shia Islam, Ali ar-Ridha moved to Merv and lived there for several years. Merv also became the centre of a major 8th-century Neo-Mazdakite movement led by al-Muqanna, the "Veiled Prophet", who gained many followers by claiming to be an incarnation of God and heir to Abu Muslim; the Khurramiyya inspired by him, persisted in Merv until the 12th century. During this period Merv, like Samarqand and Bukhara, functioned as one of the great cities of Muslim scholarship; the celebrated historian Yaqut (1179–1229) studied in its libraries. Merv produced a number of scholars in various branches of knowledge, such as Islamic law, hadith, history, and literature. Several scholars have the name "Marwazi" (المروزي) designating them as hailing from Merv. The city continued to have a substantial Christian community. In 1009, the Archbishop