The Tai-Shan people are believed to have migrated from Yunnan in China. The Shan are descendants of the oldest branch of the Tai-Shan, known as "Tai Luang" ('Great Tai') or Tai Yai ('Big Tai'). The Tai-Shan who migrated to the south and now inhabit modern-day Laos and Thailand are known as "Tai Noi" (or "Tai Nyai"), while those in parts of northern Thailand and Laos are commonly known as "Tai Noi" ('Little Tai' - Lao spoken) The Shan have inhabited the Shan Plateau and other parts of modern-day Burma as far back as the 10th century CE. The Shan kingdom of Mong Mao (Muang Mao) existed as early as the 10th century CE but became a Burmese vassal state during the reign of King Anawrahta of Pagan (1044–1077).