The history of Assam is the history of a confluence of peoples from the east, west and the north; the confluence of the Indo-Aryan, Austro-Asiatic and Tibeto-Burman cultures. Politically, it has been invaded, but has never served as a vassal or a colony to an external power till the advent of the Burmese in 1821 and subsequently the British in 1826.

The history of Assam is known from many sources. The Ahom kingdom of medieval Assam maintained chronicles, called Buranjis, written in the Ahom and the Assamese languages. History of ancient Assam comes from rock inscriptions and the many copper plates and royal grants the Kamarupa kings issued during their reign. Protohistory is reconstructed from folklore, epics like Mahabharata, and two medieval texts compiled in the Assam region—the Kalika Purana and the Yogini Tantra.

Assam was known as 'Kamarupa' or 'Pragjyotish' in the period of the Epics. Human inhabitation of this area dates backs to about 2000 BC. The population of Assam comprises of the migrants from Burma and China. They came into Assam after the mongoloid migration. They came from Punjab through Bihar and North Bengal. Thus Assam presents a fusion of Mongol-Aryan culture. The early history of Assam is believed to be of the Varman dynasty.

The reign of this dynasty extended from 400 AD to 13th century. The visit of Huien Tsang is said to have taken place during the 7th century at the time of Kumar Bhaskar Varman. The Ahoms ventured into Assam in about 1228 AD. By 15th century the kingdoms of Ahom and Koch were established. This period witnessed a change in all walks of life in Assam.

In the later part of the 18th century the Ahom Kingdom was weakened due to internal strife. The Burmese ran over the political authority in Assam thus invoking British intervention to subdue the Burmese. After a conflict between the Burmese and the English, peace was restored by the treaty of Yandaboo in 1826. The British then set out to organize the administration, transport and communication.

Besides the various changes, the construction of railways; introduction of tea plantation, discovery of coal and oil etc. proved fruitful to the British during the World War II. After Independence of India, Assam witnessed several separation of territories. In 1948, NEFA (Arunachal Pradesh) was separated. In 1963 Nagaland was separated. In 1972 Meghalaya and in 1987 Mizoram.

Paleolithic cultures: The earliest inhabitants of the region are assigned to the Middle Pleistocene period (781,000 to 126,000 years ago) in the Rongram valley of Garo Hills. The Paleolithic sites, which used handaxe-cleaver tools, have affinities to the Abbevillio-Acheulean culture. Other Paleolithic sites include those in the Daphabum area of Lohit district in Arunachal Pradesh which used stone tools from metamorphic rocks. The cave-based Paleolithic sites at Khangkhui in Ukhrul, Manipur, is placed in the Late Pleistocene period.

There exists evidence of a microlithic culture in the Rongram Valley of Garo Hills that lie between the neolithic layers and virgin soil. The microliths here were made of dolerite, unlike those from the rest of India. Shreds of crude hand-made pottery indicate that the microlithic people were hunters and food-gatherers.

The historical account of Assam begins with the establishment of Pushya Varman's Varman dynasty in the 4th century in the Kamarupa kingdom, which marks the beginning of Ancient Assam. This dynasty was most likely of aboriginal origin, but drew its lineage from Narakasura. The kingdom reached its zenith under Bhaskarvarman in the 7th century. Xuanzang visited his court and left behind a significant account.

Bhaskar Varman died without leaving behind an issue and the control of the country passed to Salasthamba, who established the Mlechchha dynasty. After the fall of the Mlechchha dynasty in the late 9th century, a new ruler, Brahmapala was elected, who established the Pala dynasty.

The last Pala king was removed by the Gaur king, Ramapala, in 1110. But the two subsequent kings, Timgyadeva and Vaidyadeva, though established by the Gaur kings, ruled mostly as independents and issued grants under the old Kamarupa seals. The fall of subsequent kings and the rise of individual kingdoms in the 12th century in place of the Kamarupa kingdom marked the end of the Kamarupa kingdom and the period of Ancient Assam.