In the 11th century, Aleppo became a contested center of power between competing Seljuk leaders and local dynasties. Alp Arslan ibn Chagri-beg faced internal conflict within the Seljuk clan early in his reign, defeating rival family members and consolidating authority. He later extended Seljuk influence into Syria and made the Mirdasid dynasty of Aleppo his vassal in 1070. After receiving the submission of
Harran and
Edessa, Mongol leader
Hulagu Khan crossed the Euphrates, sacked
Manbij and placed Aleppo under siege. Hulegu left Azerbaijan in September 1259 and sent advance forces under the
Kitbuqa Noyan ahead of the main army. The Mongol forces moved through the regions east of Lake Van, passing through Diyarbakir, where they began systematically subduing towns in Upper Mesopotamia. Hulagu himself captured several settlements, including Edessa, Nusaybin, and Harran, before advancing across the Euphrates River toward Syria. ==Siege==