On four separate occasions reality challenged Gautama's sheltered ideals. After seeing an old man, a sick man, a corpse, and a wandering holy man, Gautama left his family and assumed a life of wandering while he questioned life.

According to legend, Gautama, while sitting alone under a banyan tree, passed through the four stages of meditative trance, attained enlightenment, and thereafter began to teach.

Called Buddha ("Enlightened One"), Gautama did not claim to be divine, and he did not receive revelation from a higher being.

He taught the Four Noble Truths: Life is filled with anguish. Clinging to or seeking permanence in a world where all things change leads to anguish. Nirvana (the end of suffering) exists. And the Eightfold Path leads to nirvana and breaks the cycle of death and rebirth.

The Eightfold Path forbids theft, lying, strong drink, sexual promiscuity, and killing. It also stresses that no harm be done to any creature.

Eventually Buddhism all but disappeared in India. But by traversing the Himalaya mountains and streaming along Silk Road trade routes, the religion reached China. From there it spread to other parts of East Asia.

Today there are many forms of Buddhism practiced around the world. Theravada, the more conservative branch, dominates Southeast Asia. Zen Buddhism is practiced in Japan and China. And Lamaism, made famous by the Dalai Lama, is most common among Tibetans, despite Chinese oppression.