Tripura is a state in Northeast India. The third-smallest state in the country, it covers and is bordered by Bangladesh (East Bengal) to the north, south, and west, and the Indian states of Assam and Mizoram to the east. In 2011 the state had 3,671,032 residents, constituting 0.3% of the country's population. Indigenous communities, known in India as scheduled tribes, form about 30 per cent of Tripura's population. The Kokborok speaking Tripuri people are the major group among 19 tribes and many subtribes. The Bengali people form the ethno-linguistic majority in Tripura.
The area of modern Tripura was ruled for several centuries by the Tripuri dynasty. It was the independent princely state of the Tripuri Kingdom under the protectorate of the British Empire which was known as Hill Tippera while the area annexed and ruled directly by British India was known as Tippera District (present Comilla District). The independent Tripuri Kingdom (or Hill Tippera) joined the newly independent India in 1949. Ethnic strife between the Tripuri people and Bengali population led to tension and scattered violence since its integration into the country of India, but the establishment of an autonomous tribal administrative agency and other strategies have led to peace.
Tripura lies in a geographically disadvantageous location in India, as only one major highway, the National Highway 44, connects it with the rest of the country. Five mountain ranges—Boromura, Atharamura, Longtharai, Shakhan and Jampui Hills—run north to south, with intervening valleys; Agartala, the capital, is located on a plain to the west. The state has a tropical savanna climate, and receives seasonal heavy rains from the south west monsoon. Forests cover more than half of the area, in which bamboo and cane tracts are common. Tripura has the highest number of primate species found in any Indian state. Due to its geographical isolation, economic progress in the state is hindered. Poverty and unemployment continue to plague Tripura, which has a limited infrastructure. Most residents are involved in agriculture and allied activities, although the service sector is the largest contributor to the state's gross domestic product.
Mainstream Indian cultural elements, especially from Bengali culture, coexist with traditional practices of the ethnic groups, such as various dances to celebrate religious occasions, weddings and festivities; the use of locally crafted musical instruments and clothes; and the worship of regional deities. The sculptures at the archaeological sites Unakoti, Pilak and Devtamura provide historical evidence of artistic fusion between organised and tribal religions. The Ujjayanta Palace in Agartala was the former royal abode of the Tripuri kings.
Although there is no evidence of lower or middle Paleolithic settlements in Tripura, Upper Paleolithic tools made of fossil wood have been found in the Haora and Khowai valleys. The Indian epic, the Mahabharata; ancient religious texts, the Puranas; and the Edicts of Ashoka – stone pillar inscriptions of the emperor Ashoka dating from the third century BCE – all mention Tripura. An ancient name of Tripura is Kirat Desh (English: "The land of Kirat"), probably referring to the Kirata Kingdoms or the more generic term Kirata. However, it is unclear whether the extent of modern Tripura is coterminous with Kirat Desh. The region was under the rule of the Twipra Kingdom for centuries, although when this dates from is not documented. The Rajmala, a chronicle of Tripuri kings which was first written in the 15th century, provides a list of 179 kings, from antiquity up to Krishna Kishore Manikya (1830–1850), but the reliability of the Rajmala has been doubted.
 Tripura became a princely state during British rule in India. The kings had an estate in British India, known as Tippera district or Chakla Roshnabad (now the Comilla district of Bangladesh), in addition to the independent area known as Hill Tippera, the present-day state. Udaipur, in the south of Tripura, was the capital of the kingdom, until the king Krishna Manikya moved the capital to Old Agartala in the 18th century. It was moved to the new city of Agartala in the 19th century. Bir Chandra Manikya (1862–1896) modelled his administration on the pattern of British India, and enacted reforms including the formation of Agartala Municipal Corporation.
Following the independence of India in 1947, Tippera district – the estate in the plains of British India – became a part of East Pakistan, and Hill Tippera remained under a regency council until 1949. The Maharani Regent of Tripura signed the Tripura Merger Agreement on 9 September 1949, as a result of which Tripura became a Part C state of India. It became a Union Territory, without a legislature, in November 1956 and an elected ministry was installed in July 1963. The geographic partition that coincided with the independence of India resulted in major economic and infrastructural setbacks for the state, as road transport between the state and the major cities of India had to follow a more circuitous route. The road distance between Kolkata and Agartala before the partition was less than , and increased to , as the route now avoided East Pakistan. The geo-political isolation was aggravated by an absence of rail transport.
Some parts of the state were shelled by the Pakistan Army during the Indo-Pakistani War of 1971. Following the war, the Indian government reorganised the North East region to ensure effective control of the international borders – three new states came into existence on 21 January 1972: Meghalaya, Manipur, and Tripura. Since the partition of India, many Hindu Bengalis have migrated to Tripura as refugees from East Pakistan; settlement by Bengalis increased at the time of the Bangladesh Liberation War of 1971. Before independence, most of the population were indigenous; now they became a minority. Ethnic strife between the tribes and the predominantly immigrant Bengali community led to scattered violence, and an insurgency spanning decades. This gradually abated following the establishment of a tribal autonomous district council and the use of strategic counter-insurgency operations, aided by the overall socio-economic progress of the state. Tripura remains peaceful, as of 2012.