Chutiya Kingdom
During the earlier part of the 13th century, when the Ahoms established their rule over Assam with the capital at Sivasagar, the Sovansiri area and by the banks of the Disang river were under the control of the Chutias. According to popular Chutia legend, Chutia king Birpal established his rule at Sadiya in 1189. He was succeeded by ten kings of whom the eighth king Dhirnarayan or Dharmaraj had a son, Sadhak Narayan and a daughter Sadhani. In his old age he handed over his kingdom to his son-in-law Nitai or Nityapal. Later on Nityapal’s incompetent rule gave an opportunity to the Ahom king Suhungmung Dihingia Raja, who annexed it to the Ahom kingdom. Sadhani and Nityapal committed suicide.

Medieval History (12th to early 19th century AD)
The first Mohammedan invasion (1206 & 1226) of Kamrupa took place during the reign of a king called Prithu who was killed in a battle with Ilitutmish in 1228.During the second invastion by Ikhtiyaruddin Yuzbak or Tughril Khan, about 1257, the king of Kamrupa Saindhya (1250-1270) transferred  the  capital  Kamrup  Nagar‘  to  Kamatapur  in  the  west.  From  then  onwards,  Kamata’s ruler was called Kamateshwar.

According to traditions, Lower Assam and the adjacent part of Bengal subsequently formed a kingdom called Kamata, and its ruler at the beginning of the fourteenth century was  Durlabh Narayan (1330-1350). He is followed by Indranarayan and probably he was the last ruler of this dynasty.During the last part of 14th century, Arimatta was the ruler of Gaur (the northern region of former Kamatapur) who had his capital at Vaidyagar. The last descendent of Arimatta was Mriganka, who died childless, followed by the rule of the Bhuyans and after the invasion of the Mughals in the 15th century many muslims settled in this State and can be said to be the first Muslim settlers of this region.

In the 15th century a line of Khen kings rose to power and Nilambar, the third and the last of this line, was overthrown in 1498 by Hussain Shah, who after  a long  seize, took the capital, Kamatapur by his stratagem.

First Mohammedan Invasion of Kamrupa
In 1206  the  Afghan Muhammad-i-Bakhtiyar  (Bakhtiyar  Khilji  ) passed  through  Kamarupa  against Tibet which ended in disaster, the  first  of  many  Turko-Afghan  invasions.  The ruler  of  Kamarupa  at this point was Prithu (d. 1228, called Britu in Tabaqat-i Nasiri), who is sometimes identified with Visvasundara, the son of Vallabhadeva of the Lunar dynasty, mentioned in the Gachtal inscription of 1232  A.D. Prithu  withstood  invasions  (1226–27)  from Ghiyasuddin   Iwaj   Shah of Gauda who retreated, but was killed in the subsequent invasion by Nasiruddin Mahmud in 1228.

Nasiruddin installed a tributary king but after his death in 1229, the control of Kamarupa lapsed back to local rulers.

Kingdom of Kamata
From among the local rulers, there emerged a strong ruler named Sandhya (c.1250–1270), the Rai of Kamrup, with his capital at Kamarupanagara, the seat of the last Pala kings.

Malik Ikhtiyaruddin Iuzbak, a governor of Gaur for the Mamluk rulers of Delhi,  attempted  an invasive attack on Sandhya’s domain in 1257; and Sandhya, with the help of the spring floods that same year, captured and killed the Sultan. Subsequent to this attack,  Sandhya  moved his  capital from Kamarupanagara to Kamatapur (North Bengal) and established a new kingdom, that came to be called Kamata.At that time, western Kamarupa was the domain of the Koch and Mech peoples. In other   parts   of    the    erstwhile    Kamarupa,    the Kachari    kingdom (central    Assam,    South bank), BaroBhuyans (central Assam, North bank), and the Chutiya kingdom (east) were emerging. The Ahoms, who would establish a strong and independent kingdom later, began building their state structures in the region between the Kachari and the Chutiya kingdoms in 1228.

BAROBHUYANS
The Bhuyans were petty chiefs who had their petty principalities towards the east of Kamrup- Kamata area. They were politically aware and accordingly they made the adjustments, sometimes accepting the suzerainty of kings more powerful than them or sometimes declaring their independence.

The  title  ―Baro‖  is  a  title  of  honour  given  to  twelve  chieftains  who,  even  though  were  not  kings, established in their independence they stood united against any common enemy. They took up arms against the Ahoms also, but it was the Ahom king Pratap Singha who crushed the rebellion of the Barobhuyans. Mention here should also be made of Srimanta Sankardeva, the most illustrious of the Bhuyans.

Khen Dynasty
The Khen dynasty replaced the weak rulers of Kamata kingdom following Arimatta in the middle of the 15th century. Niladhvaj Khen, the first king, united several Baro-Bhuyan chieftains of the area and removed the last of Arimatta’s successors—Mriganka.

There were only three Khen rulers. The last king, Nilambar expanded the kingdom to include the present Koch Bihar districts of West Bengal and the undivided Kamrup and Darrang districts of Assam and northern Mymensing in Bangladesh as well as eastern parts of Dinajpur district, though he was removed by Alauddin Husain Shah in 1498.

According to the Gosani Mangala (1823), the Khen rulers had a humble origin, implying that they were local indigenous chieftains. They worshiped Kamatashwari (also  called Chandi or Bhavani), thus providing a break from the earlier dynasties that drew their lineage from Narakasura, the son of Vishnu i.e Bhauma dynasty. The Khen rulers were of Kheng-Bhutanese lineage from  the mountains. Possibly non-Aryan in origin, it was only the decline of the Kamarupa kings  which allowed them to blossom into a powerful entity in their own right from their former position as local chieftains.

The Khen dynasty finally fell to Alauddin Husain Shah in 1498. But Hussein Shah could not rule the kingdom—Bhuyan chiefs of the region, with the help of the Ahom king, Suhungmung, defeated the invaders in 1505. Soon the control of the Kamata kingdom passed into the hands of the Koch dynasty.After the collapse of the Palas of the Kamrupa Kingdom, western Kamarupa was the domain of the Koch and Mech peoples – kamata, Khen and Koch Kingdoms. In other parts of the erstwhile Kamarupa, the Kachari kingdom (central Assam, South bank), BaroBhuyans (central Assam, North bank), and the Chutiya kingdom (east) were emerging. The Ahoms, who would establish a strong and independent kingdom later, began building their state structures in the region between the Kachari and the Chutiya kingdoms in 1228.

Kachari Kingdom
The Dimasa Kingdom (also Hidimbā kingdom) was a  major  kingdom  in  Assam, Northeast  India ruled by Dimasa kings,    called Timisa in     the Ahom Buranjis. The     Dimasa     kingdom     and     others (Kamata, Chutiya) that developed in the wake of the  Kamarupa kingdom were examples of new states that emerged from indigenous communities in Medieval Assam that  transformed  these  communities. The British finally annexed the kingdom: the  plains in  1832  and the hills  in  1834.  This  kingdom gave its  name  to undivided  Cachar  district of colonial  Assam.  And  after  independence  the  undivided Cachar district was split into three  districts  in  Assam: Dima  Hasao  district (formerly North  Cachar Hills), Cachar district, Hailakandi district.

In the beginning of the 13th century, when the Ahoms appeared on the political scene of Assam, the Kacharis were the  most important and organised tribe with  their kingdom extending  fromthe  river.

Dikhou in the east to the Kapili in the west and covering the present district of North Cachar in the south. The Kacharis have no written records o their rule. According to certain traditions, there were two branches of Kacharis, one ruling at sadiya and the other on the south bank of the Brahmaputra with capitals at Dimapur, Maibong and Khaspur.

The southern branch of the Dacharis claimed their esent from Ghatotkacha, son  of Bhima, through the Kachari princess Hedamba or hidimba. As for the Sadiyal Kacharis their identity is not fully established.The Kacharis are known under different names in different places throughout north-east India. In goaplara and North Bengal they are called Mech and in North Cachar Hills Dimasa. In the Brahmaputra valley, the Kacharis call themselves Bodo or Bodo-fisa.

The first encounter of the Kacharis with the Ahoms took place about the end of the 15th century. The Ahoms were defeated and compelled to sue for peace. This humiliation was fully retaliated by Suhungmung or the Dinihgia Raja, who inflicted a crushing defeat on the Kacharis in 1526 AD and made them feudatory to the Ahoms. Henceforth the Kachari kings were called thapita sancita of the Ahoms. But soon afterwards, the Kacharis revolted against the Ahoms  who led an army  to subdue the rebels, killed their king and took possession of their capital city Dimapur.

The Kacharis then moved downwards and established their headquarters at Maibang on the bank the Mahur river, but the Ahom  kings  did not refrain from considering the Kacharis as being  in virtual subordination.The Kacharis were conquered by the Koches in 1562 and Kamalnarayan, popularly known as Gosain Kamal, who was another brother of Naranarayan, the Koch king, was appointed governor of Cachar.

This had stopped Ahom intervention in Kachari affairs as the Ahoms also by that time had become tributary to the Koches. However following the defeat of the Koches in Bengal (1567-68), the rulers of the north-eastern states reasserted their independence.

JAINTIA KINGDOM

The Jaintia   Kingdom was   a    matriarchal    kingdom    in    present-day Bangladesh’s Sylhet Division and India’s Meghalaya state. It was partitioned into three in 630 AD by Raja Guhak for his three  sons,   into  the   Jaintia   Kingdom, Gour   Kingdom and Laur   Kingdom.   It  was  annexed  by the British East India Company in 1835.

Jayantia was a matriarchal race which had established their kingdom in and around Jayantia hills. This race forged matrimonial relation with the Ahoms and fought alongside during the invasion of the Mughals.

In the 17″ century Jayantia king Dhanmanik helped the Ahoms in the war against the Kacharis. One of their ruler, Jashomatta Rai was the contemporary of the Ahom king Nariya Raja (1644-1648). He claimed back the possession of Dimoria, Gobha,  Nellie  and  Khola  principalities  which  led  to  the souring  of  relations  between  the  Jayantias  and   the  Ahoms.  Bijayanarayan  was  the  last  Jayantia ruler after whom this kingdom passed into the hands of the British along with the Ahom kingdom.