The Black Banner or Black Standard (, also known as (, "banner of the eagle" or simply as , , "the banner") is one of the flags flown by the Islamic prophet Muhammad according to Muslim 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). The Black Banner, which is distinct from the ISIS flag, has been used by some jihadist and other militant groups since the 1990s, including some Chechen groups. Scholars have interpreted IS's use of a similar black flag as representing their claim to re-establishing a Caliphate. Similar black flags have been used throughout Islamic history, including in Afghanistan during the early 20th century. Origin The Roman army used visible standards, Eagles, to identify the core of its legions. By the mid-600s, Arab armies were using standards for the same purpose. Among these forces the was a square banner; not to be confused with the or , an identifying mark like a red turban. Islamic tradition states that the Quraysh had a black and a white-and-black . It further states that Muhammad had an in white nicknamed "the Young Eagle" (, ); and a in black, said to be made from his wife Aisha's head-cloth. This larger flag was known as Eagle. The hadith reports Muhammad said that the advent of the Mahdi would be signalled by Black Standards proceeding from Khorasan and that it will be the flag of the army that will fight the Masih ad-Dajjal. At the Battle of Siffin, according to tradition, Ali used the of the Prophet, which was white while those who fought against him instead used black banners. Historical use The Abbasid Revolution against the Umayyad Caliphate adopted black for its for which their partisans were called the s. Their rivals chose other colours in reaction; among these, forces loyal to Marwan II adopted red. The choice of black as the colour of the Abbasid Revolution was already motivated by the "black standards out of Khorasan" tradition associated with the Mahdi. The contrast of white vs. black as the Fatimid vs. Abbasid dynastic colour over time developed in white as the colour of Shia Islam and black as the colour of Sunni Islam. After the revolution, Islamic