First sermon painting, Wat Chedi Liem, Thailand.

According to the Buddhist tradition, the historical Buddha Siddharta Gautama was born to the Shakya clan, at the beginning of the Magadha period (546–324 BCE), in the plains of Lumbini (Ancient India in what is now southern Nepal). He is also known as the Shakyamuni (literally "The sage of the Shakya clan").

After an early life of luxury under the protection of his father, Suddhodana, the ruler of Kapilavastu (later to be incorporated into the state of Magadha), Siddharta entered into contact with the realities of the world and concluded that real life was about inescapable suffering and sorrow. Siddharta renounced his meaningless life of luxury to become an ascetic. He ultimately decided that asceticism was also meaningless, and instead chose a middle way, a path of moderation away from the extremes of self-indulgence and self-mortification.

Under a fig tree, now known as the Bodhi tree, he vowed never to leave the position until he found Truth. At the age of 35, he attained Enlightenment. He was then known as Gautama Buddha, or simply "The Buddha", which means "the enlightened one".

For the remaining 45 years of his life, he traveled the Gangetic Plain of central India (region of the Ganges/Ganga river and its tributaries), teaching his doctrine and discipline to an extremely diverse range of people.

The Buddha's reluctance to name a successor or to formalise his doctrine led to the emergence of many movements during the next 400 years: first the schools of Nikaya Buddhism, of which only Theravada remains today, and then the formation of Mahayana and Vajrayana, pan-Buddhist sects based on the acceptance of new scriptures and the revision of older techniques.