This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Huynh Phu So was born in 1920 in Hoa Hao village, An Giang province, in the Mekong Delta, and founded Hoa Hao Buddhism there on July 4, 1939, at the age of nineteen, after a reported cure from long illness that followers took as a sign of spiritual power. A founding built on a personal healing narrative, rather than on years of prior religious study or institutional standing, gave the new movement an immediacy that drew followers quickly around him.
He preached a simplified, lay centred Buddhism practised at home rather than through temple ritual or monastic intermediation, a deliberate simplification that lowered the barrier to practice for ordinary Mekong Delta farmers who had no easy access to temples or monks. Between 1939 and 1947 he composed the poems and prose later collected as the Sam Giang, the movement's core teaching text, work he continued across the same years his following and his political prominence both grew rapidly.
His following spread quickly across the Mekong Delta, and within less than a decade of his founding sermon Huynh Phu So had become a significant political as well as religious figure amid Vietnam's wartime upheaval.