Analysis of information sources in references of the Wikipedia article "Al-Hariri of Basra" in English language version.
Staying in Mosul until the death of Sultān Muhammad Tapar in 1118, Zangi then entered the service of the Sultān's son and the new Seljuk ruler Mahmūd (1118-1119), remaining loyal to him to the end. With the new era introduced with the defeat of Sultān Mahmūd in the Sāveh battle he engaged his uncle Sanjar in 1119, which opened the way for Sanjar (1119-1157) to accede to the throne of Great Seljuk Empire, Mahmūd was assigned to the Iraqi Seljuk Sultānate (1119-1131), continuing his rule there. In 1124, Sultān Mahmūd granted the city of Wasit to Imad al-Din Zangi as a ıqta, and conferred him the Military Governorship of Basra together with Baghdad and Iraq in 1127. The reason behind such assignments was to attempt to impede Abbasid Caliph al-Mustarshid (1118-1135) who then wished to build a worldwide dominance. Indeed, the efforts of Zangi in the fight of Mahmūd, whom Sanjar urgently sent to Baghdad, against the Caliph ensured the Sultān became victorious, and he contributed to the efforts in damaging the sole authority and dominance claims of the Caliph. Following the deaths of Mosul Governor Aq-Sunqur el-Porsuqi and his successor and son Mas'ud in the same year in 1127, Zangi was appointed Governor of Mosul. He was also in charge of al-Jazeera and Northern Syria, and Sultān Mahmūd approved him being assigned as the Atabeg of his two sons, Farrukh shāh and Alparslan. Thus the Atabegdom of Mosul was formed.
Staying in Mosul until the death of Sultān Muhammad Tapar in 1118, Zangi then entered the service of the Sultān's son and the new Seljuk ruler Mahmūd (1118-1119), remaining loyal to him to the end. With the new era introduced with the defeat of Sultān Mahmūd in the Sāveh battle he engaged his uncle Sanjar in 1119, which opened the way for Sanjar (1119-1157) to accede to the throne of Great Seljuk Empire, Mahmūd was assigned to the Iraqi Seljuk Sultānate (1119-1131), continuing his rule there. In 1124, Sultān Mahmūd granted the city of Wasit to Imad al-Din Zangi as a ıqta, and conferred him the Military Governorship of Basra together with Baghdad and Iraq in 1127. The reason behind such assignments was to attempt to impede Abbasid Caliph al-Mustarshid (1118-1135) who then wished to build a worldwide dominance. Indeed, the efforts of Zangi in the fight of Mahmūd, whom Sanjar urgently sent to Baghdad, against the Caliph ensured the Sultān became victorious, and he contributed to the efforts in damaging the sole authority and dominance claims of the Caliph. Following the deaths of Mosul Governor Aq-Sunqur el-Porsuqi and his successor and son Mas'ud in the same year in 1127, Zangi was appointed Governor of Mosul. He was also in charge of al-Jazeera and Northern Syria, and Sultān Mahmūd approved him being assigned as the Atabeg of his two sons, Farrukh shāh and Alparslan. Thus the Atabegdom of Mosul was formed.