The Koch–Ahom conflicts[1] (1532–1571) refer to the diplomatic, strategic and military relationships between the Koch and the Ahom kingdoms over the control of the Brahmaputra Valley.
Though an initial contact between the Ahoms and Koch occurred during Biswa Singha's reign, the relationship became belligerent with Nara Narayana ascending to power and consolidating his hold over the western portion of Assam; and it ended with the failure of Chilarai's campaign against Sulaiman Karrani.
[2] Biswa Singha (r. 1515–1540), on the advice of his ministers, made peace and accepted the status of being a protectorate with an annual tribute of horses; and in return was gifted the land west of Sankosh the Ahoms had received as dowry from the Sultan.
[3] Biswa Singha was initially regular in payments, but after having consolidated his newly established rule decided to invade the Ahom kingdom instead.
In 1537 he advanced up to Singari, in Nagaon district, but had to give up his ambitions due to problems in supplying his forces[4]—subsequently he and his brother attended the court of Suhungmung in the winter of that year.
[6] Following the example of his father, Nara Narayan was assisted by his brother Sukladhwaj (also Chilarai) who was the Diwan (prime minister) as well as the commander-in-chief of the Koch army.
[7] There was a succession issue in the Ahom kingdom as well when Suhungmung was assassinated in 1539 in a conspiracy hatched by his son Suklenmung who succeeded him.
The renewal of hostilities in 1546 costed the lives of those three Koch princes and Naranarayan launched an expedition against the Ahom kingdom.