It expanded suddenly under Suhungmung in the 16th century[12] and became multi-ethnic in character, casting a profound effect on the political and social life of the entire Brahmaputra valley.

Though it came to be called the Ahom kingdom in the colonial and subsequent times, it was largely multi-ethnic, with the ethnic Tai-Ahom people constituting less than 10% of the population toward the end.

[14] The Ahoms initially called their kingdom Mong Dun Shun Kham till 1401 (Assamese: xunor-xophura; English: casket of gold), but adopted Assam in later times.

[16] The Ahom kingdom was established in 1228 when Sukaphaa, a Tai prince, entered the Brahmaputra valley having crossed the rugged Patkai mountain range from Mong Mao.

[17] Sukaphaa probably started his journey from his homeland with a small number, but he was supported and joined by other Tai chiefs and common followers along the way[18] and entered Assam with approximately 9,000 persons.

[19][20] His destiny was Upper Assam, earlier the domain of the Kamarupa kingdom but which had since lapsed into deteriorating conditions,[21] and his intention was not to conquer and raid but to permanently settle in fallow land and practice agriculture[22] The Ahoms were primarily responsible for converting the undulating alluvial forest and marshy plains in upper Assam to flat rice fields able to hold plain water for rice cultivation via a network of embankments.

[23] The Tai-Shans had with them the basic political structures for state-building (Mung), surplus producing technologies such as sedentary wet-rice cultivation and hydrology, a patriarchal social organisation based on clans (foid), and a literary form of their language.

Nevertheless the later Tungkhungia kings veered towards Saktism[27] and the persecution of the shudra Mahantas and their laity that began during the reign of Siva Singha led to the Moamoria rebellion and ultimately to the eclipse of the kingdom.

[34] At the time of their advent, the Ahoms came with advanced technologies of rice cultivation, and it was their belief that they were divinely ordained to turn fallow land to agriculture and also to absorb stateless and shifting agriculturists to their own ways.

[44] At the end of the 14th century, the nascent Ahom polity faced crises of succession, two regicides, and three quick interregnum periods when the kingdom was without a king.

[45] Sudangphaa Bamuni Konwar (r. 1397–1407), born and raised in a Brahmin household in Habung, was identified as a descendant of a past king and installed on the throne by the Burhagohain and Borgohain to end the period of crisis.

[53] The Ahom royalty continuously improved their relationship with the Brahmans which enabled them to gain goodwill with the Indo-Aryanized tribal groups and consolidate power.

[55] It began first with a consolidation of the militia in 1510,[56] followed by an expansion into the Bhuyan region at Habung in 1512 (probably with the help of the descendants of the Habungia Brahmans settled during Sudangpha's time[57]).

[62] These expansions created significant changes in the kingdom—the Assamese-speaking Hinduized subjects outnumbered the Ahoms themselves;[63] and the absorption of the Chutia kingdom meant a wide range of artisan skills became available to it increasing the scope for division of labour.

[66] The nature of the kings institutional relationship to the ministers changed with the creation of a new position, the Borpatrogohain, named after a Chutia office;[67][68] and the creation of the offices of Sadiyakhowa Gohain (territories acquired from the Chutia kingdom)[69] and the Marangikhowa Gohain (territories acquired from the Kachari kingdom),[61] both of which were reserved for the Borgohain and Burhagohain lineages.

[71] And when the Ahoms under Ton Kham Borgohain[72] pursued the invaders and reached the Karatoya river[73] they began to see themselves as the rightful heir of the erstwhile Kamarupa kingdom.

Unable to keep it, and in at the end of the Battle of Saraighat, the Ahoms not only fended off a major Mughal invasion but extended their boundaries west, up to the Manas river.

Gadadhar Singha came in conflict with the Vaisnava Satras who began commencing immense power and influence over the state and people, and started a wide–spread persecution of the Vaisnavites.

The Tungkhungia regime witnessed a relative time of peace till first half of the 18th century, where the population increased, trade expanded, Coinage and monetization made headway.

He had made extensive preparations to extend the boundary west–towards, attempted to make a confederacy of Hindu kings of eastern India against Mughals.

From his death bed he expressed his will that, all his five sons to be kings in an executive manner and advised them to take initiation of Parvatiya Gosain[80] Siva Singha alias Sutanphaa (r. 1714–1744), he dropped his father's plan to invade Benagal.

Siva Singha reign was peaceful, except an expedition sent against the Daflas, he had caused the erection of many temples and made numerous grants to the religious sites and brahmanas.

Rajeswar Singha alias Supremphaa (r. 1751–1759), he was put on the throne by Kirti Chandra Borbarua by setting aside the claims of seniority of his elder brother Barjana Gohain.

Rajeswar Singha had erected the most number of temples among the Ahom Kings, he was an orthodox Hindu and took initiation of Nati–Gosian (a relative of Pravatiya Gosain).

[86] The later phase of the rule was also marked by increasing social conflicts, leading to the Moamoria rebellion were able to capture and maintain power at the capital Rangpur for some years but were finally removed with the help of the British under Captain Welsh.

Inscriptions dating from the reign of Siva Singha, gives the price of number of commodities like rice, ghee, oil, pulses, goat, pigeon in connection with worship in different temples of the kingdom.

Due to trade with Tibet, a coin of Jayadhwaj Singha carries a single Chinese character on each side reading Zang Bao.

This piece evidently was an attempt by Jayadhwaj Singha to facilitate trade with Chinese knowing person coming from the direction of Tibet.

[88] Rudra Singha is also said to have established an extensive trade with Tibet and to have encouraged intercourse with other nations although he strictly limited the extent to which foreigners were allowed into the country.

As the perakagaz were not durable, copper plates called as tamrapatraor phali were issued for important records, particularly of revenue-free lands gifted to religious sites or to Brahamanas.