Drenpa’s Proclamation, dating from the 11th century C.E., is the earliest known coherent account, told from the perspective of the Bon religion, of how and why it came to pass that Buddhism was introduced into Tibet during the Tibetan Empire (a period that ended in 842 C.E.). Bon emerged in the 10th-11th century C.E. in Central Tibet, in the context of the ‘Later Propagation’ of Buddhism in Tibet in the same period, but was viewed by its adherents as distinct from Buddhism and as having flourished in Tibet for centuries before the advent of Buddhism. Drenpa’s Proclamation is here translated in its entirety for the first time. It contains unique insight into how Tibetans in the 12th century envisaged the religion of their ancestors, and a wealth of information about cosmological, mythological, and ritual topics.