The founding of Shan states inside the present-day boundaries of Burma began during the Pagan Kingdom in the Shan Hills and accelerated after 1287, when the Pagan Kingdom fell to the Mongols. The Shans, who came south with the Mongols, stayed, and quickly came to dominate much of northern to the eastern arc of Burma—from northwestern Sagaing Division to Kachin Hills to the present-day Shan Hills. The most powerful Shan states were Mong Yang (Mohnyin) and Mong Kawng (Mogaung) in present-day Kachin State, followed by Hsenwi (Theinni), Hsipaw (Thibaw) and Mong Mit (Momeik) in present-day northern Shan State. Smaller Shan states, such as Kale in northwestern Sagaing Division, Bhamo in Kachin State, Yawnghwe (Nyaungshwe) and Kengtung (Kyaingtong) in Shan State, and Mong Pai (Mobye) in Kayah State, played a precarious game of paying allegiance to more powerful states, sometimes simultaneously.