This abridged account of the historical Buddha's passing and entry into Nirvana is taken primarily from the Maha-parinibbana Sutta, translated from the Pali by Sister Vajira & Francis Story. Other sources consulted are Buddha by Karen Armstrong (Penguin, 2001) and Old Path White Clouds by Thich Nhat Hanh (Parallax Press, 1991).
Forty-five years had passed since the Lord Buddha's enlightenment, and the Blessed One was 80 years old. He and his monks were staying in the village of Beluvagamaka (or Beluva), which was near the present-day city of Basrah, Bihar state, northeast India. It was the time of the monsoon rains retreat, when the Buddha and his disciples stopped traveling.