The integration of Central Asia into the Islamic empire during the VIIIth and IXth c. is here analyzed through the history of its nobility and military elites. With the caliphs Ma'mun and Mu'tasim, these nobles and soldiers, both Iranian and Turkish, took part in the government of the Muslim Empire in Iraq. They brought to Baghdad and Samarra their Central Asian hierarchies and the Abbasid elites were under their influences for half a century. But the slow decay of this Central Asian military system in Samarra gave way to the political disorders of the 860's. The mamluk system was then created in the 870's to better manage the Turkish cavalrymen. French Text.