Early career Yalbugha was purchased as a
mamluk by Sultan
an-Nasir Hasan, hence Yalbugha's second
nisba (adjective denoting origin), "an-Nasiri". It is not clear when or from whom Yalbugha was purchased, Moreover, Steenbergen believes Yalbugha was purchased by an-Nasir Hasan in 1350, when the young sultan began to establish his own
mamluk power base, according to Mamluk-era historian
al-Maqrizi. As
amir majlis, he was responsible for overseeing the sultan's governmental meetings and became significantly involved in the sultan's administration. From this commanding location and fortified headquarters, Yalbugha began building his own power base of
mamluks. The contemporary narrative told by
Ibn Kathir states that an-Nasir Hasan's extravagant spending and unpopular fiscal policies precipitated the confrontation between an-Nasir Hasan and Yalbugha. Yalbugha began opposing an-Nasir Hasan in his decisions, many of which were unpopular in certain Mamluk circles. While most of the sources do not elaborate on what happened to an-Nasir Hasan afterward other than that he was never heard from again, al-Maqrizi asserts that Yalbugha had an-Nasir Hasan severely tortured, then killed and buried in a stone bench in his house where Yalbugha normally mounted his horse. Yalbugha's power was challenged by the Mamluk governor of
Damascus, Baydamur al-Khwarizmi, who declared a rebellion against him in Syria in the summer of 1361. Yalbugha also proceeded to appropriate the wealth of the Qalawunid estate, using his close relationship with Ibn Qazwina, a
Coptic convert to Islam and the
wazir (financial
vizier) of the sultan, to achieve that end. With the abundant financial resources of the sultanate at his disposal, Yalbugha built up a formidable
mamluk corps, known in modern sources as the "Yalbughawiyya", whose ranks consisted of different groupings of
mamluks, including those purchased by Yalbugha and those who came from dissipated
mamluk households. who become sultan in 1382. Yalbugha instituted training and educational reforms that rolled back the permissiveness of an-Nasir Muhammad's reign and aimed to restore the discipline and organization of the
mamluk regiments. His policy was similar to that introduced by the previous sultans
Baybars and Qalawun. In response, Yalbugha undertook major efforts to reconstruct the Mamluk navy. In less than one year and despite the dearth of building material, Yalbugha managed to oversee the production of one hundred warships, each carrying 150 sailors and a number of
mamluks. Prior to the navy's reconstruction, in late February 1366, the
mamluk factions of Yalbugha and Taybugha entered into major clashes in the outskirts of Cairo, ending years of peaceful cooperation between the two emirs as they competed for supremacy in the sultanate. Yalbugha's forces were victorious and Taybugha and his partisans were imprisoned in
Alexandria. On 14 December, Yalbugha was captured. In an apparent ruse, they brought him a horse to escape their custody, but as soon as he mounted it, one of his
mamluks, Qaratamur, beheaded him with his sword. The motive behind Yalbugha's death was attributed to his attempt to return to the traditional methods of
mamluk training, which the
mamluks perceived to be harsh and unjust. His death at their hands precluded any similar initiatives by later Bahri emirs for fear of sharing Yalbugha's fate. According to historian Amalia Levanoni, while Baybars and Qalawun faced little
mamluk opposition in their training methods, by the time Yalbugha emerged to emulate them, the
mamluks had been long accustomed to the laxness of an-Nasir Muhammad's reign and were unwilling to forfeit their material improvement for the sake of disciplinary or organizational reform. ==Domestic policies==