Under which dynasty did this Persian general serve who used the Black Standard in his uprising leading to the Abbasid Revolution in 747?
Abbasid dynasty
Title: Abu Muslim
Passage: 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.
Title: Black Standard
Passage: 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).
Title: Siege of Wasit
Passage: The Siege of Wasit involved the army of the Abbasid Revolution under al-Hasan ibn Qahtaba and the future Caliph al-Mansur, and the Umayyad garrison of Wasit under the last Umayyad governor of Iraq, Yazid ibn Umar ibn Hubayra.  Yazid had been forced to abandon Kufa due to a rebellion by Abbasid sympathizers, and fled to Wasit, where he was besieged for 11 months, from August/September 749 to his surrender in June/July 750.  The siege was marked by constant sallies and attacks, but as it progressed, the Umayyad garrison's morale collapsed and the internal divisions among the Qays and Yaman tribes began to manifest themselves.  After news of the defeat of the Umayyad Caliph Marwan II at the Battle of the Zab and the Abbasid conquest of Syria arrived at Wasit, defections began.  Yazid nevertheless held out for a few more months, until he received a pardon for himself and his followers from the Abbasid Caliph al-Saffah.  Nevertheless, Yazid and his senior officers were executed soon after on al-Saffah's orders.
Abu Muslim Black Standard