This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Buddhism reached Vietnam by two disputed early routes, and historians disagree over which came first: possibly directly from India as early as the third or second century BCE, and separately overland from China from around the first century CE onward. Whichever route came first, the earliest well documented episode belongs to the late second century CE, when the Indian monks Mahajivaka and Kalacarya arrived at Luy Lau, near modern Bac Ninh, then a hub on the maritime trade route linking the Indian subcontinent to China.
By the time the two monks arrived, Luy Lau had already become a major regional centre of Mahayana Buddhism in its own right, with sutra translation work under way there well before Buddhism's own more famous later arrival further north in China. The settlement's position on the trade route gave it an unusually early and direct connection to Indian Buddhist teaching, rather than the faith reaching Vietnam only at second hand through Chinese intermediaries.
What this changed for Buddhism's spread was the planting of the tradition in Vietnam through a direct maritime link to India, alongside and possibly ahead of its overland spread through China. Luy Lau's early translation work placed Vietnam among the genuinely early centres of Mahayana Buddhist scholarship in East Asia, not merely a later recipient of a faith already established elsewhere.