Except the kingdom of Jayantia, Ahom relations with the Kacharis , the Khasis and Garos were quite cordial. Assam’s contacts with the Garos were mainly confined to the tribes living in the south bank of the Brahmaputra and the Ahom policy was one of conciliation and friendship so that commercial intercourse could be there.
Sukapha sent a series of campaigns to the neighbouring countries which were ruled at that time by the Chutias, the Morans, the Borahis, the Nagas, the Kacharis and the most powerful kingdom of the region, Kamrup. After having conquered the countries of the Chutias, the Kacharis and the Kamata king, Sukapha allowed them to remain as they were in the past on condition of offering tribute.
The Borahi king Badancha and the Moran king Thakumtha acknowledged the supremacy of the Ahom king and regularly supplied him thenceforward with the various products of the jungles, elephants, dye, honey and mats, Sukapha wisely adopted facilitatory measures towards those people and by treating them as equals and encouraging intermarriage, he united them into one nation.
Practically Sukapha conquered the whole of upper Assam the tract south-west of the Chutias and the east of the Kacharis to the Patkai Range at the border of upper Burma and founded his capital Charaideo, in the modern district of Sibsagar. He had also conquered all the countries on the way from upper Burma to the eastern border of upper Assam and appointed his nobles to rule over those regions. He made friendship with his brother rulers in his ancestral home in upper Burma, and sent those presents of gold & silver.