Around the 10th century, the city-states of Dvaravati coalesced into two mandalas – the Lavo (modern Lopburi) and the Supannabhum (modern Suphanburi). According to a legend in the Northern Chronicles, in 903, a king of Tambralinga invaded and took Lavo and installed a Malay prince to the Lavo throne. The Malay prince was married to a Khmer princess who had fled an Angkorian dynastic bloodbath. The son of the couple contested for the Khmer throne and became Suryavarman I, thus bringing Lavo under Khmer domination through personal union. Suryavarman I also expanded into Isan, constructing many temples.Suryavarman, however, had no male heirs and again Lavo was independent. King Anawratha of Bagan invaded Lavo in 1057 and took a Lavo princess as his wife. The power of the Lavo kingdom reached the zenith in the reign of Narai (1072–1076). Lavo faced Burmese invasions under Kyanzittha, whose mother was the Lavo princess, in 1080 but was able to repel. After the death of Narai, however, Lavo was plunged into bloody civil war and the Khmer under Suryavarman II took advantage by invading Lavo and installing his son as the King of Lavo.
The repeated but discontinued Khmer domination eventually "Khmerized" Lavo. Lavo was transformed from a Theravadic Monic Dvaravati city into a Hindu Khmer one. Lavo became the entrepôt of Khmer culture and power of the Chao Phraya basin. The bass relief at Angkor Wat showed a Lavo army as one of the subordinates to Angkor. However, one interesting note is that a Tai army was shown as a part of Lavo army, a century before the establishment of the Sukhothai kingdom
