Question: Under which dynasty did this Persian general serve who used the Black Standard in his uprising leading to the Abbasid Revolution in 747?

full_context: Document 1: Abbasid Revolution: The Abbasid Revolution refers to the overthrow of the Umayyad Caliphate (661–750 CE), the second of the four major Caliphates in early Islamic history, by the third, the Abbasid Caliphate (750–1258 CE). Coming to power three decades after the death of the Muslim prophet Muhammad and immediately after the Rashidun Caliphate, the Umayyads were a feudal Arab empire ruling over a population which was overwhelmingly non-Arab as well as primarily non-Muslim. Non-Arabs were treated as second class citizens regardless of whether or not they converted to Islam, and this discontent cutting across faiths and ethnicities ultimately led to the Umayyads' overthrow. The Abbasid family claimed to have descended from al-Abbas, an uncle of the Prophet.
Document 2: Black Standard: The Black Banner or Black Standard (Arabic: راية السوداء‎ ‎ "rāyat as-sawdāʾ", also known as راية العقاب "rāyat al-ʿuqāb" "banner of the eagle" or simply as "ar-rāya " "the banner") is one of the flags flown by Muhammad in Islamic tradition. It was historically used by Abu Muslim in his uprising leading to the Abbasid Revolution in 747 and is therefore associated with the Abbasid Caliphate in particular. It is also a symbol in Islamic eschatology (heralding the advent of the Mahdi).
Document 3: Ishaq al-Turk: Ishaq al-Turk (also: Eshaq El-Tork, Arabic إسحاق الترك). Abbasid propagandist for Abu Muslim sent to the Turks of Transoxania, hence the name "al-Turk" (of the Turks). After Abu Muslim's murder at the orders of al-Mansur, he fled to Transoxania, and declared a revolt on al-Mansur. He claimed that Abu Muslim was a prophet who was sent to reform Zoroastrianism, thus starting one of many movements claiming prophethood or divinity for Abu Muslim. He also claimed descent from Yahya ibn Zayd ibn Ali ibn Abi Talib, but is most likely an ethnic Persian. The Abbasid ruler of Khorasan had him captured and executed. His group continued to be known as al-Muslimiyya "(followers of Abu Muslim Khorasani)," and constitute the fundamental ideology of the sect well known as Bābak’iyyāh in the future.
Document 4: Abna' al-dawla: The abnāʾ al-dawla (meaning "sons of the regime/dynasty"), often simply " the "Abnāʾ"", is a term for the Khurasani Arabs who had participated in the Abbasid Revolution of 749–750 and their descendants, who settled in Baghdad and Iraq. They became the ruling elite of the Abbasid Caliphate and formed the mainstay of the caliphal army. However, the term appears rarely in the sources until the time of the Fourth Fitna civil war in the 810s, when it is applied to the Khurasanis of Baghdad, who overwhelmingly supported Caliph al-Amin against his brother al-Ma'mun. The terms "ahl Khurāsān" ("people of Khurasan") and "abnāʾ ahl Khurāsān" ("sons of the people of Khurasan") are more frequently used for the Khurasanis who formed the mainstay of the Abbasid regime in general. Following al-Ma'mun's victory in the civil war, the "abnāʾ al-dawla" were largely replaced by the latter's Persian followers, and under his successor al-Mu'tasim, the rise of the Turkish slave-soldiers to power began.
Document 5: Abu Muslim: Abu Muslim Abd al-Rahman ibn Muslim al-Khorasani or al-Khurasani (Arabic: أبو مسلم عبد الرحمن بن مسلم الخراساني‎ ‎ born 718-19 or 723-27, died in 755), born Vehzādān Pūr-i Vandād Hormoz (Persian: وهزادان پور ونداد هرمزد‎ ‎ ), was a Persian general in service of the Abbasid dynasty, who led the Abbasid Revolution that toppled the Umayyad dynasty.
Document 6: Caliphate: A caliphate (Arabic: خِلافة‎ ‎ "khilāfa") is a territory under the leadership of an Islamic steward known as a caliph ( , Arabic: خَليفة‎ ‎ "khalīfah ",    ), a person considered a religious successor to the Islamic prophet Muhammad (Muhammad ibn ʿAbdullāh) and a leader of the entire Muslim community. Historically, the caliphates were polities based in Islam which developed into multi-ethnic trans-national empires. During the medieval period, three major caliphates existed: the Rashidun Caliphate (632–661), the Umayyad Caliphate (661–750) and the Abbasid Caliphate (750–1258). The fourth major caliphate, the Ottoman Caliphate, established by the Ottoman Empire in 1517, was a manifestation whereby the Ottoman rulers claimed caliphal authority. During the history of Islam, several other Muslim states, almost all of them hereditary monarchies, have claimed to be caliphates.
Document 7: Islamic Golden Age: The Islamic Golden Age is the era in the history of Islam, traditionally dated from the 8th century to the 13th century, during which much of the historically Islamic world was ruled by various caliphates, and science, economic development and cultural works flourished. This period is traditionally understood to have begun during the reign of the Abbasid caliph Harun al-Rashid (786 to 809) with the inauguration of the House of Wisdom in Baghdad, where scholars from various parts of the world with different cultural backgrounds were mandated to gather and translate all of the world's classical knowledge into the Arabic language. This period is traditionally said to have ended with the collapse of the Abbasid caliphate due to Mongol invasions and the Siege of Baghdad in 1258 AD. A few contemporary scholars place the end of the Islamic Golden Age as late as the end of 15th to 16th centuries.
Document 8: Succession to Muhammad: The succession to Muhammad raises questions about the leadership of Islam after his death: Muhammad's successor, how they should be elected, conditions of legitimacy and the role of successor. Answers to these questions have led to several divisions in the Muslim community since the first century of Muslim history, giving rise to the Sunni, Shia and Khawarij schools. After Muhammad's death in AD 632, disagreement broke out over who should succeed him as leader of the Muslim community. Since none of his sons survived into adulthood, hereditary succession was not an option. Umar (Umar ibn al-Khattab), a prominent companion of Muhammad, nominated Abu Bakr. Others added their support, and Abu Bakr was made the first caliph. This choice was disputed by some of Muhammad's companions, who believed that Ali (Ali ibn Abi Talib), the Prophet's cousin and son-in-law, had already been designated as his successor by the Prophet. During the First and Second Fitnas the Islamic community divided into a number of groups, each of which had a specific idea about successorship. After the Rashidun caliphate evolved into monarchies and sultanates, Sunnis held power in most areas; Shias emerged in opposition.
Document 9: Khazim ibn Khuzayma al-Tamimi: Khazim ibn Khuzayma al-Tamimi (  749–768 ) was a Khurasani Arab military leader. One of the early supporters of the Abbasid "da'wa" in Khurasan, he played a major role in the Abbasid Revolution against the Umayyads, and then spent the next two decades suppressing revolts across the Caliphate. As one of the main figures of the "Khurasaniyya", the main power base of the Abbasid regime, he cemented his family in a position of power and influence: his sons would play an important role in the affairs of the Caliphate over the next decades.
Document 10: Alid revolt of 762–763: The Alid revolt of 762–763 or Revolt of Muhammad the Pure Soul was an uprising by the Hasanid branch of the Alids against the newly established Abbasid Caliphate. The Hasanids, led by the brothers Muhammad (called "the Pure Soul") and Ibrahim, rejected the legitimacy of the Abbasid family's claim to power. Reacting to mounting persecution by the Abbasid regime, in 762 they launched a rebellion, with Muhammad rising in revolt at Medina in September and Ibrahim following in Basra in November. The lack of co-ordination and organization, as well as the lukewarm support of their followers, allowed the Abbasids under Caliph al-Mansur to react swiftly. The Caliph contained Muhammad's rebellion in the Hejaz and crushed it only two weeks after Ibrahim's uprising, before turning his forces against the latter. Ibrahim's rebellion had achieved some initial successes in southern Iraq, but his camp was riven by dissent among rival Shi'a groups as to the prosecution of the war and future political objectives. In the end, Ibrahim's army was decisively defeated at Bakhamra in January 763, with Ibrahim dying of his wounds shortly after. The failure of the rebellion did not mark the end of Alid unrest, but it consolidated the power of the Abbasid dynasty.
Document 11: Muslim ibn Aqeel: Muslim ibn Aqil Al-Hashimi (Arabic: مسلم بن عقيل الهاشمي) was the son of Aqeel ibn Abu Talib and a member of the clan of Bani Hashim, thus, he is a cousin of Husayn ibn Ali. The people of Kufa called upon Husayn to overthrow the Umayyad dynasty who was on his way to Mecca for the Hajj pilgrimage. He wanted to confirm the loyalty of the people of Kufa, so he sent his cousin and his ambassador, Muslim ibn Aqeel, a famous warrior, to Kufa to observe the situation. He sent a letter to Husayn confirming their loyalty, before knowing that the 30,000 followers that he gained would all betray him. He was executed by the newly installed governor, Ubaydallah ibn Ziyad, on the 9th of Dhul Hijjah, 60 AH, and is buried at the back of Great Mosque of Kufa.
Document 12: Abdallah ibn Ali: Abdallah ibn al-Abbas (ca. 712 – 764 CE) was a member of the Abbasid dynasty, who played a leading role in its rise to power during the Abbasid Revolution. As governor of Syria, he consolidated Abbasid control over the province, eliminating the remnants of the Umayyad dynasty and suppressing pro-Umayyad uprisings. After the death of his nephew and first Abbasid Caliph, al-Saffah, in 754, he launched a bid for the caliphal title against al-Saffah's brother, al-Mansur, but was defeated and imprisoned. He was killed in 764.
Document 13: Battle of Aba: The Battle of Aba, which took place on August 12, 1881, was the opening battle of the Mahdist War. The incident saw Mahdist rebels, led by Muhammad Ahmad, who had proclaimed himself the Mahdi, rout Egyptian troops who had landed on Aba Island.
Document 14: Black Star of Africa: The Black Star of Africa is a black five-pointed star (★) symbolizing Africa in general and Ghana in particular. The Black Star Line, founded in 1919 by Marcus Garvey as part of the Back-to-Africa movement, modelled its name on that of the White Star Line, changing the colour from white to black to symbolise ownership by black people rather than white people. The black star became a symbol of Pan-Africanism and anti-colonialism. Described as the "Lodestar of African Freedom", the black star was used in 1957 by Theodosia Okoh in the design of the Flag of Ghana.
Document 15: Derafsh Kaviani: Derafsh Kaviani, or Derafsh Kavani, was the legendary royal standard (vexilloid) of Iran used since ancient times until fall of the Sasanian Empire. Following the defeat of the Sassanids at the Arab conquest of Persia, the Sassanid standard was recovered by one Zerar bin Kattab, who received 30,000 dinars for it. After the jewels were removed, Rashidun Caliph Umar is said to have burned the standard. The banner was also sometimes called the "Standard of Jamshid" ("Drafš-ī Jamshid"), the "Standard of Fereydun" ("Drafš-ī Freydun") and the "Royal Standard" ("Drafš-ī Kayi").
ground_truth: Abbasid dynasty