Buddha came to Sarnath to preach his message of the middle way to nirvana after he achieved enlightenment at Bodhgaya, and gave his famous first sermon here. In the 3rd century BC, Emperor Ashoka had magnificent stupas and monasteries erected here, as well as an engraved pillar. When Chinese traveller Xuan Zang dropped by in AD 640, Sarnath boasted a 100m-high stupa and 1500 monks living in large monasteries. However, soon after, Buddhism went into decline and, when Muslim invaders sacked the city in the late 12th century, Sarnath disappeared altogether. It was ‘rediscovered’ by British archaeologists in 1835.
Today it’s one of the four key sites on the Buddhist circuit (along with Bodhgaya, Kushinagar and Lumbini in Nepal) and attracts followers from around the world, especially on Purnima (or, informally, Buddha's birthday), when Buddha's life, death and enlightenment are celebrated, usually in April or May.