Bhagirath, grandfather of Isa Khan, who belonged to the Rajput community, came to Bengal from Ayodhya. He took the job of diwan under the Sultan of Bengal giasuddin mahmud. His son Kalidas Gazdani got the post after his death. Later, Kalidas embraced Islam and took the Muslim name Solaiman. Solaiman married the Sultan's daughter Syeda Momena Khatun and got the Zamindari of Sarail. Isa Khan, son of Solaiman was born in Sarail.
Following the death of Sultan Giasuddin Mahmud, his son-in-law Solaiman Khan declared him as the legal successor and revolted against the newly established Afghan rule. During this period, he was ruling the southern region almost independently and the centre of his administration was at Sarail.
After the death of sher shah in 1545, his son Islam Shah occupied the throne of Delhi and took steps for bringing Bengal under the control of a single administrative apparatus. But when Solaiman Khan refused to accept the dictates of Islam Shah, he sent two of his generals Taj Khan and Daria Khan against Solaiman. Solaiman Khan built up a strong resistance against them.
But ultimately he was defeated and killed; his two sons Isa and Ismail were taken captives and then sold off as slaves to Iranian traders.
Taj Khan Karrani became the ruler of Bengal and Bihar in 1563 AD. Isa Khan's uncle Kutub Khan became his beneficiary and got employment in his court. At this time, he freed his nephews (Isa and Ismail) from the Iranian traders in exchange for money.
On his return home, Isa Khan got the Zamindari of Sarail with the help of his uncle Kutub Khan. Following the death of Taj Khan Karrani in 1565, Isa Khan extended all help to the Afghan rulers in facing the Mughal onslaught. He helped daud khan in his chittagong campaign against the Tripura King Uday Manikya in 1573. He assisted the commander of Daud Khan's forces in ousting the Mughal flotilla from areas adjacent to sonargaon in 1575.
Daud Khan Karrani was defeated and killed during the battle of Agmahal near rajamahal in 1576. This effectively signaled the end of Afghan rule in Bangla. At this juncture, Isa Khan was running his domain almost independently. But he realised correctly that he would not be able to confront the Mughals alone with his limited force. He therefore developed friendly relations with the neighbouring Zamindars and Afghan commanders; with their participation, he formed an anti-Mughal political and military alliance. He also established friendly relations with the kings of neighbouring Tripura and Kamrup, namely Amar Manikya and Raghudeb. Besides, Isa Khan ensured the proper use of his battleships, which were the mainstay of his military might.
The Mughal Subedar khan jahan advanced towards isa khan in 1578 and set up his military camp at bhawal. Isa Khan confronted the Mughal force at Kastaley (under Kishorganj district) near Sarail. During the initial stage of the battle, Isa Khan sought the help of king Amar Manikya after suffering losses. The Mughal forces made a retreat when Tripura king allied with him. According to descriptions by Rajmala, the Zamindar of Sarail Isa Khan sent one thousand laboueres for the Tripura King along with other Zamindars of Bengal in response to the request made by Amar Manikya when diggers were needed for excavating the 'Amar Sagar Dighi' at around 1580 AD. Besides, he fought against the zamindar of Taraf Fateh Khan in 1581 as the naval commander of Amar Manikya.
Isa Khan continued to build up his forces in East Bengal by taking advantage of the revolts by Mughal commanders against Emperor Akbar in 1580. He declared himself as the ruler of the southern region in 1581-82 and took the title of 'Masnad-i-Ala'. From Sarail, he shifted his administrative centre to Sonargaon. He built fortresses at katrabo, Kalagachhia and Khizrpur near Sonargaon.
Masum Khan Kabuli and Katlu Khan, two rebel commanders of Akbar joined hands with Isa Khan. Akbar appointed General Azam as the Subahdar of Bengal and gave orders for conducting a campaign against Isa Khan, who had provided sanctuary to the Mughal commanders. During this period, Isa Khan fought against the Mughal commander Shahbaz Khan at Tokey and Tarsun Khan at Bajitpur. The Mughal forces were defeated in those battles. The Mughal General Shahbaz Khan once again conducted a campaign against Isa Khan in 1584. The battlefields stretched across a vast area including Dhaka, Bikrampur, Sonargaon and Katrabo. Isa Khan was successfully keeping the Mughals at bay. He could establish his authority over almost the whole of the southern region during this time and set up his capital at Katrabo on the bank of Lakhya river. It may be mentioned that Isa Khan assumed the leadership of the 'Bara Bhuiyans' even before 1584. ralph fitch could obtain similar information from the descriptions in 1586.
In 1586, Isa Khan defeated the chieftain of Jangalbari, Kishorganj Luxman Hajra. In the same year, Mughal Subahdar Shahbaz Khan again sent his forces against Isa Khan to the south. But apparently this campaign by the Mughals also turned out to be futile. There were no more wars between Isa Khan and the Mughals for the next ten years.
In 1588, Isa Khan fought battles against chand rai and kedar rai. Raja Mansingh came to Bengal in 1595 after getting appointment as the Subahdar. He took preparations for running a campaign against Isa Khan. In 1597, Mansingh sent two forces against Isa Khan on land and water. The Mughal forces led by Mansingh's son Durjan Singh achieved some success initially. They even attacked Isa Khan's capital Katrabo. Isa reached a place twelve miles from bikrampur along with his allied forces. There was a fierce battle between the two forces when the Mughal navy was surrounded on all four sides (September 1597). On the Mughal side, many people including Durjon Singh were killed and Isa Khan took several Mughal soldiers captive. After that, there were no more wars between Isa Khan and the Mughal forces.
Emperor Akbar could not establish his authority in the southern region of East Bengal during Isa Khan's lifetime. During this period, Isa Khan transformed the region into an independent kingdom by establishing his authority over the large areas. Isa Khan passed away in September 1599. [ABM Shamsuddin Ahmed]