The Pyu was the early advanced civilization of Burma. The Pyu were organized into 18 city states. The Burmese founded the Kingdom of Pagan in the Irrawaddy Valley. Their King Anawratha conquered the Mon Kingdom in 1058 AD. In the 13th century, Pagan was sacked by the troops of Kublai Khan. This gave the chance for the Mons to regain their independence. The Mon had migrated to Eastern Burma and Thailand from India and Burma.
The state of Dvaravati in Thailand, between the 6th and the 11th centuries, was the leading Mon kingdom. Another Mon kingdom rose in 573 AD. From the 10th century onwards, the Mon kingdoms were pushed back, or defeated by Pagan and the Khmer. The Mon of Northern Thailand lived in a kingdom centred around Lamphun. They were defeated by the Thai king, Mangrai in 1283.