It was in light of this close alliance that
Islam Khan I, the Mughal governor of
Bengal, when initiating hostilities against Khwaja Usman in March 1612, also dispatched an imperial force against Bayazid so as to prevent the latter from providing aid. Ghiyas Khan was appointed to lead the expedition, though due to his diffidence, command was later entrusted to
Shaikh Kamal. He was assisted by officers such as
Mubariz Khan, Tuqmaq Khan,
Mirak Bahadur Jalair and Mir Abdur Razzaq Shirazi. Mir Ali Beg was made the
bakhshi (paymaster) of this Mughal command. The host consisted of four thousand
matchlock-men, one thousand picked cavalry of Islam Khan I, one hundred imperial war elephants and the fleet of Musa Khan and his confederates, who had surrendered to the Mughals the previous year. Bayazid's side consisted of the forces sworn to him and his brother Yaqub, as well as several hill-tribe chieftains (likely
Kukis). Upon reaching the outskirts of Bayazid's domains, the Mughals launched a series of plundering raids with the intention of terrorising the inhabitants into submission, eventually arriving on the banks of the
Surma River just outside the
city of Sylhet. To challenge Shaikh Kamal's advance, Bayazid deputised his brother to lead a large contingent to the region and man the fort of Kadamtala. In turn, Shaikh Kamal dispatched
Raja Satrajit to construct their own
blockhouse fort on the Surma bank opposite, though throughout its construction, they faced continuous bombardment by cannon fire from Yaqub's men. Upon its completion and after a week of artillery fire, the Mughals were able to capture Kadamtala, forcing the Afghans to retreat. However, upon receiving considerable reinforcements from the
Raja of Kachar, Bayazid and Yaqub resumed their hostilities, attacking the imperial fort to the result of a serious loss of life on both sides. The intense conflict continued, putting Shaikh Kamal in considerable difficulties. The Afghans reached such levels of confidence that they repeatedly sent messages offering to accept the Mughals' surrender: "we still promise you and all your comrades, great and small, a safe passage. If you desire your welfare, then come out of your fort and go you all back on foot to Islam Khan with your bare bodies, leaving all your elephants and equipments here." However, when news was received of the defeat and death of Khwaja Usman, the Afghans were greatly demoralised, with their resistance collapsing and Bayazid quickly suing for peace. After initially sending Yaqub to treat with the Mughal command, Bayazid was instructed to go personally and offer his unconditional surrender. Shaikh Kamal met him with civility and offered him and his brother
robes of honour as well as the promise of imperial favour. Thus assured, Bayazid surrendered his elephants to the Mughal general, who ordered Mubariz Khan and another subordinate to command the occupying soldiers and administration of Sylhet respectively. Soon after, Anwar Khan also submitted, thus bringing Sylhet for the first time under the control of the Mughal empire. ==Aftermath==