How Buddhism Spread Across Asia and Returned to India

The starting point is the Buddha's own teaching career in the fifth century BCE, with the first sermon traditionally placed at Sarnath, decades of travel across the kingdoms of Magadha and Kosala, and the formation of the first monastic community, the sangha.

Ashoka's missionary embassy, led by Mahinda in most chronicle accounts, converted King Devanampiya Tissa at Mihintale, and his sister Sanghamitta brought a branch of the Bodhi tree and founded the island's order of nuns.

Along the Silk Road, the Kushan Empire gave Buddhism its institutional footing from the first to third centuries CE, with centres such as Bamiyan and Hadda becoming hubs from which the tradition continued east.

Buddhism entered China gradually, and by the second century CE monk-translators such as Lokaksema and An Shigao were rendering sutras into Chinese at Luoyang; the story of Emperor Ming's dream is recorded here as a later legend.

In 372 CE the monk Sundo reached the Goguryeo court of King Sosurim with texts and images, and Seongmunsa was built for him; Baekje followed in 384 and Silla by the 530s, each on a separate mission.

Around 538 King Seong of Baekje sent images and sutras to Emperor Kinmei, and the Soga clan championed the new religion against opposing clans, a conflict that shaped its early political fortunes.

Songtsen Gampo introduced Buddhism to the Tibetan court in the seventh century, but it only became secure in the eighth, when Trisong Detsen invited Padmasambhava and Shantarakshita and Samye was founded, followed by a royal edict in 791.

From 1044 King Anawrahta gave a Theravada reform movement state backing in Myanmar, and over the next two and a half centuries it spread to Thailand, Cambodia and Laos, which all still hold it as the dominant tradition.

Around 1193 Bakhtiyar Khilji's campaign into Bihar burned Nalanda and destroyed nearby monasteries, ending the institutional base of Indian Buddhism; the atlas records this as political and institutional destruction, not a doctrinal defeat.

On 14 and 15 October 1956 B.R. Ambedkar led a mass conversion at Deekshabhoomi in Nagpur, and India's Buddhist population rose from roughly 181,000 in 1951 to over three million within five years.