Factional strife within the local Mamluq ruling group weakened their power, and led to a progressive loss of control over the Arab tribes in Iraq. In 1801 their weakness was revealed by their inability to defend the great Shi’ite shrine of Karbala from a sack by Sunni tribesmen.
Successive attempts by the Ottoman government in Constantinople to re-assert control over the country continued to fail, until 1831. In that year, however, the integrity of the empire was threatened by Mohammed Ali of Egypt, who occupied Syria. The Ottoman government in Constantinople then made a determined effort to reimpose control over Iraq by sending in a powerful army. In the following years they have been able to extend their rule throughout the entire country.
ORIGINAL SOURCE: timemaps.com