One of the most senior Western representatives of the Thai Forest Tradition of Theravāda Buddhism, Sumedho is considered a seminal figure in the transmission of the Buddha's teachings to the West.

After a year as a Red Cross social worker, Jackman served with the Peace Corps in Borneo from 1964 to 1966 as an English teacher.

On break in Singapore, sitting one morning in a sidewalk café, he watched a Buddhist monk walk by and thought to himself, "That looks interesting."

In 1975, he helped to establish and became the first abbot of the International Forest Monastery, Wat Pa Nanachat in northeast Thailand founded by Ajahn Chah for training his non-Thai students.

Amaravati is part of the network of monasteries and Buddhist centres in the lineage of Ajahn Chah, which now extends across the world, from Thailand, New Zealand and Australia, to Europe, Canada, and the United States.

His successor is the English monk Ajahn Amaro, hitherto co-abbot of the Abhayagiri branch monastery in California's Redwood Valley.

Like most teachers in the Forest Tradition, Ajahn Sumedho tends to avoid intellectual abstractions of the Buddhist teachings and focuses almost exclusively on their practical applications, that is, developing awareness and wisdom in daily life.