Guha Amalendu. Medieval and Early Colonial Assam: Society, Polity, Economy

South Asia Books, 1991. — 309 p.The Chutiya (1187–1673 CE), a Bodo-Kachari group by origin, held the regions on both the banks of Brahmaputra with its domain in the area eastwards from Vishwanath (north bank) and Buridihing (south bank), in Upper Assam and in the state of Arunachal Pradesh. It was partially annexed in the early 1500s by the Ahoms, finally getting absorbed in 1673 CE. The rivalry between the Chutiyas and Ahoms for the supremacy of eastern Assam led to a series of battles between them from the early 16th century until the start of the 17th century, which saw great loss of men and money. The Dimasa, another Bodo-Kachari dynasty, (13th century-1854 CE) ruled from Dikhow River to central and southern Assam and had their capital at Dimapur. With the expansion of Ahom kingdom, by the early 17th century, the Chutiya areas were annexed and since c. 1536 CE the Kacharis remained only in Cachar and North Cachar, and more as an Ahom ally than a competing force. The Ahoms, a Tai group, ruled Upper Assam. The Shans built their kingdom and consolidated their power in Eastern Assam with the modern town of Sibsagar as their capital. Until the early 1500s, the Ahoms ruled a small kingdom in Sibsagar district and suddenly expanded during King Suhungmung's rule taking advantage of weakening rule of Chutia and Dimasa kingdoms. By 1681, the whole track down to the border of the modern district of Goalpara came permanently under their sway. Ahoms ruled for nearly 600 years (1228–1826 CE) with major expansions in the early 16th century at the cost of Chutia and Dimasa Kachari kingdoms. Since c. the 13th century CE, the nerve centre of Ahom polity was upper Assam; the kingdom was gradually extended to the Karatoya River in the 17th or 18th century. It was at its zenith during the reign of Sukhrungphaa or Sworgodeu Rudra Sinha (c. 1696–1714 CE). The Koch, another Bodo-Kachari dynasty, established sovereignty in c. 1510 CE. The Koch kingdom in Western Assam and present-day North Bengal was at its zenith in the early reign of Nara Narayan (c. 1540–1587 CE). It split into two in c. 1581 CE, the western part as a Mughal vassal and the eastern as an Ahom satellite state. Later, in 1682, Koch Hajo was entirely annexed by the Ahoms. Despite numerous invasions, mostly by the Muslim rulers, no western power ruled Assam until the arrival of the British. Though the Mughals made seventeen attempts to invade, they were never successful. The most successful invader Mir Jumla, a governor of Aurangzeb, briefly occupied Garhgaon (c. 1662–63 CE), the then capital, but found it difficult to prevent guerrilla attacks on his forces, forcing them to leave. The decisive victory of the Assamese led by general Lachit Borphukan on the Mughals, then under command of Raja Ram Singha, in the Battle of Saraighat in 1671 almost ended Mughal ambitions in this region. The Mughals were comprehensively defeated in the Battle of Itakhuli and expelled from Lower Assam during the reign of Gadadhar Singha in 1682 CE.