Funan, Chenla and Angkor

By at least the start of the first millennium CE, the territory of what is now southern Việt Nam formed an integral part of the proto-Khmer kingdom of Funan, the capital of which was located at
Óc Eo in modern An Giang Province. The first Shivaite state in South East Asia, Funan is known to have been a major maritime power which at its height embraced southern Việt Nam, much of Cambodia and parts of the Malay peninsula.
First excavated by French archaeologist Louis Malleret in the 1940s,
Óc Eo Citadel embraced an area of some 1,100 acres and incorporated brick foundations and an extensive system of canals. Visiting the region in around 250 CE while exploring sea passages to India, Chinese envoys Kang Dai and Zhu Ying described Funan as a sophisticated country with its own taxation system, ruled by a king who lived in a walled palace.

Malleret's excavations unearthed many valuable artefacts, including pottery with intricate floral designs, gold and silver currency, jewellery, statues and reliefs of the Buddha and Hindu gods such as Ganesh and Vishnu, and trade goods from as far afield as Rome, India and China.
Since 1975 many more excavations have been carried out in neighbouring provinces, revealing thousands more valuable relics of the Óc Eo-Funan civilisation. Apart from
Óc Eo Citadel itself, the most important Óc Eo-Funan archaeological sites in the lower Mekong Delta are
Gò Tháp in Đồng Tháp Province,
Bình Tả in Long An Province,
Nền Chùa and
Vòng Xoài in Kiên Giang Province,
Gò Thành in Tiền Giang Province and
Lưu Cừ II in Trà Vinh Province.
By the 6th century Funan was in decline; between 550 and 680 it became integrated with one of its former vassal-states, resulting initially in the formation of two interlinked kingdoms – Water or Lower Chenla, centred at Angkor Borei (modern-day Takeo Province of Cambodia), and Land or Upper Chenla, which incorporated a large area stretching from modern Kompong Thom Province of Cambodia into what is now Champassak Province of Laos. Thereafter these two kingdoms began to develop into a unified Khmer state, a process consolidated following the accession in 802 of King Jayavarman II, founder of Angkor.

Over the next 400 years the Angkorian kings expanded their sphere of influence as far as the Malay peninsula in the south, to the Burmese border in the west and to the frontier of the nascent Đại Việt kingdom in the north east.
At least two regions of southern Việt Nam - modern Tây Ninh Province and modern Bạc Liêu Province - appear to have been important regional centres, first of Chenla and subsequently of Angkor. Foundations of temples and other buildings may be found in profusion throughout both provinces, although regrettably only three
prasats have survived, namely
Chót Mạt Tower and
Bình Thạnh Tower in Tây Ninh Province and
Vĩnh Hưng (Trà Long) Tower in Bạc Liêu Province.
Southern Việt Nam was to remain under Khmer control until 1749, and while little is currently known about the Proto-Khmer and Khmer heritage of this region, it is anticipated that future archaeological study will reveal a great deal more.