The Princely State of Rembrai, also known as Rambrai state, was a princely state of India that existed during the rule of the British Empire in India. In the 19th century, the region was allotted as one of the princely states of India which was managed by native princes under the indirect rule of the British authorities. The state was covered a total area of 328 sq miles and comprised of a total population of 3,151 in the year 1941. The princely state of Rembrai was included as a part of the states of Khasi kingdom in Meghalaya, located in northeastern India, south of Bhutan, which was under the rule of the British Province of Assam. The taluka of Rembrai was located towards the northern part of the Western Khasi States.

Location of Rembrai
The erstwhile princely state was bordered by the British Province of Assam in the north; by the princely state of Nongkhlaw in the east; by the princely state of Myriaw to the south; and by the princely state of Nongstoin in the west. The former native state included around 49 villages. The territory of Rembrai was under the administrative control of the States of Assam Agency.

History of Princely State of Rembrai
The princely state of Rembrai, like other States in the Khasi Kingdom, was established when villages merged together for mutual protection against the adjacent territories, namelky the villages of Domspep, Synia and Mawdoh. The native ruler held the title of Syiem. There were 2 major branches of the ruling family of the Syiem, namely the Black Syiems and the White Syiems. During the 19th century, members of both the families were elected rulers and the ruling families asserted the right to alternate in the rulership with the other Syiem branch. The Syiem was appointed by the Lyngdohs of the 3 villages. In the year 1829, the province came under protection of the British East India Company. The native ruler of the state, along with 2 ministers, took charge of the administration on one side of the Khri River, while the 3 Lyngdohs possessed jurisdictional authority of the other side.

The native ruler or Syiem of Rembrai was succeeded by his eldest brother, failing which, by the ruler's eldest nephews, grand nephews, or cousins, in no particular order, but at all times in the female line. The princely state of Rembrai had no provision for the appointment of a female as the native ruler of the region. Although this system did not provide total claim to succession, as the Electoral College might have disqualified the heirs from the succession due to several reasons under Khasi custom and religion. Around 24 eminent individuals, including the sardars of the villages, 1 mantra and 3 Lyngdohs, recommended the nomination of the native ruler of Rembrai state. The Syiem was then decided by the people of the state.

Accession of Princely State of Rembrai
After the Partition of India and the departure of the British Government of India in the year 1947, the state was acceded to the newly independent Union of India, which also known as the Dominion of India, by the Syiem of Rembrai state. At present the territory is located in Meghalaya.