Abbasid Muslim caliph dynasty (750–1258). They traced their descent from al-Abbas, the uncle of Muhammad, and came to power by defeating the Umayyads. In 862 the Abbasids moved the caliphate from Damascus to Baghdad, where it achieved great splendour. From the 10th century Abbasid caliphs ceased to exercise political power, becoming religious figureheads. After the family's downfall in 1258, following the fall of Baghdad to the Mongols, one member was invited by the Mamluk sultan to Cairo where the dynasty was recognized until the 16th century.

Abbasid a member of a dynasty of caliphs who ruled in Baghdad from 750 to 1258, named after Abbas (566–652), the prophet Muhammad's uncle and founder of the dynasty.