Much of the ancient past of Assam still lies buried deep beneath its soil. Lack of proper and systematic archaeological research has resulted in a dearth of archaeological material, and though evidence of human habitation in the land has been traced back to the Early Stone Age, the overall picture remains vague and indistinct. That Assam , by whatever name, was known in other parts of the world as far back as in 100 BC is nevertheless clear from the records of the Chinese explorer Chang Kien who traced his country's trade with Assam during that period. The Periplus of the Erythrean sea depicts how Chinese silk from Assam reached Egypt and Rome before the advent of Christainity. Ptolemy's geography also acknowledges the existence of Assam.

The land of Assam was known by various names in the past---Pragjyotishpura in ancient Hindu scriptures like the Mahabharata; and Kamarupa in the early medieval times. After the decline of the Kamarupa kingdom in the 12th century, the land that included a part of the old Kamarupa kingdom and regions to the east of it was ruled by the Shan people, who called themselves Tai, but who were called Ahoms by the others. This kingdom lasted for nearly 600 years. The earliest ruler according to legend was a mlechchha (non-Aryan) ruler named Mahiranga (sanskritized form of the Tibeto-Burman name Mairang). He was followed by others in his line: Hatakasura, Sambarasura, Ratnasura and Ghatakasura. Naraka removed this line of rulers and established his own dynasty. Historians consider Naraka's victory over the mlechchha rulers to mark the beginning of sanskritization in this region. The Naraka king mentioned at various places in Kalika Purana, Mahabharata and Ramayana covering a wide period of time were probably different rulers from the same dynasty. Kalika Purana, a sanskrit text compiled in Assam in the 9th and 10th century, mentions that the last of the Naraka rulers, Narakasura, was slain by Krishna . His son Bhagadatta, mentioned in the Mahabharata, fought for the Kauravas in the battle of Kurushetra with an army of kiratas, chinas and dwellers of the eastern coast. Later rulers of Kamarupa frequently drew their lineage from the Naraka rulers.

Medieval Assam was known as Kamarupa or Kamata, and was ruled by many dynasties. Chief among them was the Varman Dynasty (350-650). During the rule of the greatest of the Varman kings, Bhaskarvarman (600-650), a contemporary of Harshavardhana of Kanauj, the Chinese traveler Xuanzang visited the region, and recorded his travels. The other dynasties that ruled the region were the Kacharis, the Chutias etc. that belonged to the Indo-Tibetan groups.

Two later kingdoms left the biggest impact in the region. The Ahoms, a Tai group, ruled eastern Assam for nearly 600 years (1228-1826). The Koch, a Tibeto-Burmese/Dravidian group, established their sovereignty in 1510 which later extended to western Assam and northern Bengal . The Koch kingdom later split into two. The western kingdom became a vassal of the Moghuls whereas the eastern kingdom became an Ahom satellite state.

In spite of numerous invasions from the west, mostly by Muslim rulers, no western power could establish its rule in Assam until the advent of the British. The most successful invader was Mir Jumla, a governor of Aurangzeb, who briefly occupied Gargaon the then capital of the Ahoms (1662-1663). He found it difficult to control the people, who carried on guerrilla attacks on his forces and forced his army to leave the region. The last attempt by the Moghuls under the command of Raja Ram Singh resulted in the victory for the Ahoms at Saraighat (1671) under the Ahom general Lachit Borphukan.

After the independence from British rule in 1947, Assam spawned four more states to become one of the seven sister states in the 1960s and 1970s. The new states were Arunachal Pradesh, Nagaland, Mizoram and Meghalaya. The capital of Assam , which was in Shillong, had to be moved to Dispur, now a part of an expanding Guwahati.In 1961, the Government of Assam passed a legislature making the usage of Assamese language compulsory. The legislature resulted in widespread protest across Assam , particularly by the significant non-Assamese speaking minority.

Capital : Dispur
Coordinates : 26.15° N 91.77° E
Largest city : Guwahati
Population (2001) : 26,638,407
Density : 340/km²
Area : 78,438 km²
Districts : 23
Time zone : IST (UTC+ 5:30 )
Official language : Assamese, Bodo, Karbi