Ajahn Chah, later known formally as Phra Bodhiñāṇa Thera, was born in 1918 in a rural farming village called Baan Kôr (also rendered Baan Gor) in Ubon Ratchathani Province in northeastern Thailand, the Isan region. He grew up in a modest rice-farming family, immersed in traditional village life and surrounded by the rhythms of agricultural work and village Buddhism. This environment was not merely a backdrop but a formative matrix, shaping his sensitivity to impermanence, hardship, and communal interdependence. From early on, he was exposed to the local temple as the center of education, ritual, and moral guidance, a setting that would later become the ground of his own teaching.

As a boy, he entered the monastery as a novice, following a common pattern in rural Thailand, and there he studied basic Buddhist teachings, chanting, and monastic discipline. After some years, he disrobed in order to return to his family and assist with the work of farming, stepping back into the life of a layperson. The death of his father became a turning point, confronting him directly with the realities of sickness, aging, and death, and awakening a deeper spiritual urgency. This experience led him to see that ordinary worldly pursuits could not offer lasting security or satisfaction.

At the age of twenty, he reordained as a fully ordained monk (bhikkhu), entering once more into the monastic life with a more resolute intention. His early years as a monk were spent in conventional monasteries where study and scholastic learning were emphasized, yet he found that intellectual understanding alone did not answer his existential questions. This dissatisfaction propelled him toward the austere forest tradition, where practice is grounded in direct experience rather than conceptual knowledge. He took up the wandering life of a forest monk (tudong), seeking out teachers who embodied strict discipline and deep meditative realization.

During these wanderings, he trained under several renowned forest masters, most notably Ajahn Mun Bhūridatta, a central figure in the Thai Forest Tradition. Under such guidance, he embraced a rigorous lifestyle that emphasized strict adherence to the Vinaya, intensive meditation, and dwelling in remote natural settings. The convergence of his rural upbringing, his early exposure to village monasticism, and his later immersion in the forest tradition gave his teaching a distinctive character. It combined the plainspoken clarity of village wisdom with the depth of lived contemplative insight, making profound Dhamma principles accessible to both monastics and lay followers.