Almanzor (al-man'-zor) (surnamed the Victorious). The second caliph of the Abbassidian Dynasty, succeeded his brother, Abul Abbas, in 754. He exterminated the race of the Ommaiades, and in 762 founded though city of Baghdad, which became the capital of his empire. Several other Mohammedan princes, famed for their martial achievements, also bore this name. He died in 775.