Shaghab or Umm al-Muqtadir (died 933) was the mother of the eighteenth Abbasid Caliph al-Muqtadir (reign 908-932), and wielded a considerable influence over state affairs during the reign of her son. She was commonly referred to only as Umm al-Muqtadir (mother of al-Muqtadir) or al-sayyida (the lady).
Shaghab was reportedly a Rumiyya, that is to say of Greek origin from the Byzantine Empire. She was originally a slave of Umm Qasim, a daughter of Muhammad ibn Abdallah ibn Tahir, the Tahirid governor of Baghdad in 851–867. Originally named Na'ima ("gentle"), at some point—it is not recorded how or when—she entered the harem of Caliph al-Mu'tadid (r. 892–902), and became his concubine. After giving birth to Ja'far, the future al-Muqtadir, in 895, she was set free (umm walad) and given the name Shaghab ("turbulent"). According to the historian Hugh Kennedy, this was a common practice at the time for girls, so as to "draw attention from their beauty, or, possibly, to ward off jealousy and misfortune".
Shaghab was influential at court, especially after the death of al-Mu'tadid's first wife, the Tulunid princess Qatr al-Nada, who had one day threatened to cut off her nose. While al-Muktafi (r. 902–908) remained the first heir, it was widely expected that her son would reign, since al-Muktafi was of sickly disposition. She also avidly promoted the careers of her own family, her sister Khatif, her brother Gharib ibn Abdallah, and her nephew Harun. Gharib became one of close circle of senior ghilmān, many of whom were of Greek origin, around al-Mu'tadid, such as the future commander-in-chief Mu'nis al-Khadim. Until his death in 917, Gharib was one of the leading commanders and provincial governors of the state. When al-Mu'tadid died and al-Muktafi became Caliph, al-Muqtadir was the target of various palace intrigues, but Shaghab could count on the devotion of al-Mu'tadid's old ghilmān to his offspring to ward off any danger to her son.