The Deori or Deuri are one of the major ethnic tribes of arunachal pradesh and assam, India. They historically live in the upper plains or hinterland of the Brahmaputra Valley. The Deori tribe belongs to the Sino-Tibetan family of Mongoloid stock (as is generally the case of the people of northeast India). In ancient times of Ahom and Sutiya kingdoms the Deoris used to serve as priests in the temples of the kingdoms and therefore the origin of the name "Deori". The tribe has maintained their racial traits, languages, religion and folk tales, beliefs through centuries. The Deori people are subdivided into four main groups namely Dibongyia, Borgoya, Tengaponiya and Patorgoya. The Patorgoya group of people is not officially traced yet and an effort is on to identify them.
The Deori people follow indigenous faith.They worship their ancestors; KundiMama-kundigirasi(shiva-parvati), Boliya Baba (pisadema) and Tameshwari (pisasi). They also worship other Hindu deities. Deoris are very religious people. Since antiquity, Deori people worshiped God by singing hymns and holy songs. Later on the experienced priests known as Bordeuri and Bharali started sacrificing animals in their temples.They used to serve as priest in the Sutiya and Ahom kingdom and hence got the name "D
However, history says that the homeland of the Deoris is in the North Eastern states of India or in the east of undivided Assam and Arunachal pradesh. According to the book Mataks and their kingdom, the Deoris lived on the bank of the Kundil river which flows through the Sadiya (Chapakhowa) area and for this reason their Kingdom in the North Eastern region of the Brahmaputra Valley was known as Chutam.
In the book "Siva Purana", the late Ahom king Rudra Singha narrates that the Deoris were living at Chaug-Chu-Kul, Chakati-Chaliya, Laibari, Lataubari, Joidaam, Arem-Kerem and Mamaru-Pichala (Now in Arunachal Pradesh).They had an honorable and prestigious king called Patgauan or Tanugiria.The first king of Dimichiya Ganarajya was Bisusing Borkoyo in 1500BC and the last king was Bismoksing Borkoyo, who was most famous and well known for his brilliance.
It is said that in 1602AD the three main sub groups of Deoris namely Jimochayan or Dibang-Diyongial, Midoyan or Tengapania and Luitugan or Borgoya took different temples like Midiya (Bolia Baba), Luituwasi, Midi Gira-Girasi (Burha-Burhi) and Daramji (Parsuram Kundha). They had been serving the 4th sub cast called Patgayan or Tanugirian. These areas are now in the Lower Dibang Valley, western Lohit and Northern Changlang and North East Tinsukia Dist. of Assam.