The Ahom or Tai Ahom is an ethnic group from the Indian states of Assam and Arunachal Pradesh. The members of this group are admixed descendants of the Tai peoples who reached the Brahmaputra Valley of Assam in 1228, along with indigenous peoples who joined them over the course of history. Sukaphaa, the leader of the Tai group and his 9,000 followers, established the Ahom kingdom (1228–1826), which controlled much of the Brahmaputra Valley until 1826, when the Treaty of Yandabo was signed.