Barmecides (descendants of Barmek), a powerful family of Khorasan, attached to the Abbasside caliphs. One of them, Khaled ben Barmek, was tutor of Haroun al-Rashid. His son Yahya became the vizier of Haroun about 786, and contributed greatly to the renown of his master's reign. Of his sons, Fadhl was distinguished as a soldier and as minister of justice, and Jaffar figures in the "Arabian Nights" as the friend and confidant of Haroun. At the same time some 25 members of the family held important civil and military dignities. The downfall of the Barmecides took place about 803. Haroun, becoming jealous of the popularity and power of the family, and incensed, it is said, on account of the birth of a son of his sister Abassa, whom he had married to Jaffar on condition that the union should be merely platonic, caused Jaffar to be beheaded at Anbar, on the Euphrates; Yahya and Fadhl were thrown into prison at Racca, where they died in chains, while nearly all their relatives were arrested and deprived of their property. Ibn Khaldun disputes the truth of this story, which in modern times has afforded a theme to poets and dramatists.

To one of the Barmecides is attributed the famous feast in the "Arabian Nights," where the guest was served with only imaginary viands; whence the phrase "Barmecide feast."