Background and early life
According to al-Suyuti's History of the Caliphs, al-Mansur lived AD 714 – 6 October AD 775 (95 AH – 158 AH) . Al-Mansur was born at the home of the Abbasid family in Humayma (modern-day Jordan) after their emigration from the Hejaz in 714 (95 AH). His mother was Sallamah, a slave woman. Al-Mansur was a brother of al-Saffah. Both were named Abd Allah, and to distinguish between them, al-Saffah was referred to by his kunya Abu al-Abbas.
Al-Mansur was a great-great-grandson of Abbas ibn Abd al-Muttalib, an uncle of the Islamic prophet, Muhammad. Al-Mansur's brother al-Saffah began asserting his claim to the caliphate in the 740s and became particularly active in Khorasan. After the death of the Umayyad caliph Hisham ibn Abd al-Malik in 743, a period of instability followed. Al-Saffah led the Abbasid Revolution in 747, and his claim to power was supported throughout Iraq. He became the first caliph of the Abbasid Caliphate in 750 after defeating his rivals.
Shortly before the overthrow of the Umayyads by the Khorasani army mobilized through the extensive underground network of the Abbasid mission, the last Umayyad caliph Marwan II arrested the head of the Abbasid family, al-Mansur's older brother Ibrahim. Al-Mansur fled with the rest of his family to Kufa, where some of the Khorasanian rebel leaders gave their allegiance to his brother al-Saffah. Ibrahim died in captivity, and al-Saffah became the first Abbasid caliph. During his brother's reign, al-Mansur led an army to Mesopotamia, where he received the submission of the local governor after informing him of the Umayyad caliph's death. The governor had taken refuge in Iraq in a garrison town. He was promised a safe-conduct by al-Mansur and the Caliph al-Saffah, but after surrendering the town, he was executed with a number of his followers.
According to The Meadows of Gold, a history book in Arabic written around 947 AD, al-Mansur's dislike of the Umayyad dynasty is well documented and he has been reported saying:
The Umayyads held the government which had been given to them with a firm hand, protecting, preserving and guarding the gift granted them by God. But then their power passed to their effeminate sons, whose only ambition was the satisfaction of their desires and who chased after pleasures forbidden by Almighty God...Then God stripped them of their power, covered them with shame and deprived them of their worldly goods.
Mansur's first wife was a Yemeni woman from a royal family; his second was a descendant of a hero of the early Muslim conquests; his third was an Iranian servant. He also had a minimum of three concubines: an Arab, a Byzantine, nicknamed the "restless butterfly," and a Kurd.
