Chah Subhaddo (Thai: ชา สุภัทโท, alternatively Achaan Chah, occasionally with honorific titles Luang Por and Phra) or in honorific name "Phra Bodhiñāṇathera" (Thai: พระโพธิญาณเถร, Chao Khun Bodhinyana Thera; 17 June 1918 – 16 January 1992) was an influential teacher of the Buddhadhamma and a founder of two major monasteries in the Thai Forest Tradition.
Read about Ajahn Chah in Wikipedia