At the age of twenty-nine Siddhartha Gautama, prince of a ruling house in Nepal, abandons the luxuries of home, and the affections of a wife and a young son, to become a wandering ascetic. He is following a pattern not uncommon in India at this time, when the rigidities of a priest-dominated Hinduism are causing many to seek a more personal religion. Only a few years previously, in a nearby district, a young man by the name of Vardhamana has done exactly the same – with lasting results in the form of Jainism. (The conventional dates for both men, revised by modern scholarship, have been a century earlier.)

Gautama differs from Vardhamana in one crucial respect. He discovers that asceticism is almost as unsatisfactory as luxury.
 
According to the traditional account (first written down in the 3rd century BC) Gautama follows an ascetic life for six years before deciding that a middle path between mortification and indulgence of the body will provide the best hope of achieving enlightenment.

He resolves to meditate, in moderate comfort, until he sees the light of truth. One evening he sits under a pipal tree at Buddh Gaya, a village in Bihar. By dawn he is literally Buddha, an 'enlightened one'. Like any other religious leader he begins to gather disciples. He becomes known to his followers as the Buddha.

The Four Noble Truths and the Eightfold Path: c.424 BC

Gautama preaches his first sermon at Sarnath, about 5 miles (8km) north of the sacred Hindu city of Varanasi. In this sermon, still a definitive text for all Buddhists, he proposes a path to enlightenment very different from the elaborate ceremonies and colorful myth attached to the Hindu deities.

Gautama's message is plain to the point of bluntness, at any rate when reduced to a simple list – as it usually is in primers on Buddhism. He states that enlightenment can be achieved by understanding Four Noble Truths; and that the pain of life, with which the Noble Truths are concerned, can be avoided by following an Eightfold Path.
 
The four Noble Truths are that pain is inextricably part of mankind's everyday life; that our cravings of all kinds are the cause of this pain; that the way off this treadmill is to free oneself of these cravings; and that this can be achieved by following the Eightfold Path.

The Path enjoins the Buddhist to a virtuous life by urging on him the 'right' course of action in eight contexts. Many of these are moral evils to be avoided (as in the Jewish Commandments). But the eighth step, 'Right Concentration', goes to the heart of the Buddhist ideal.
 
Right Concentration is described in Buddhist scripture as concentrating on a single object, so as to induce a special state of consciousness through deep meditation. In this way the Buddhist hopes to achieve complete purity of thought, leading ideally to nirvana.

Nirvana means 'blowing out', as of a flame. It is common to Hinduism and Jainism as well as Buddhism. But in the two older religions it leads to moksha, release from the cycle of rebirth, total extinction. In Buddhism it is a blissful transcendent state which can be achieved either in life or after death – and which is achieved by anyone who becomes Buddha.
 
The spread of Buddhism: c.380-250 BC

By the time of his death, at about the age of eighty, the Buddha's followers are established as communities of monks in northern India. Wandering through villages and towns with their begging bowls, eager to describe the path to the truth, they are familiar figures. But so are many other such groups, including the Jains.

The advance of the Buddhists beyond the others is largely due to the enthusiastic support of a king of the 3rd century BC. Asoka rules over much of the Indian subcontinent. His inscriptions, carved on pillars and rocks throughout his realm, bear witness both to the spread of Buddhism and to his own benevolent support of the Buddha's principles.
 
During Asoka's reign, and with his encouragement, Buddhism spreads to south India and into Sri Lanka. The latter has remained to this day a stronghold of the earliest form of Buddhism, known as Theravada (meaning the 'school of elders').

By the time of Asoka there is already a rival tendency within Buddhism, involving an elaboration of the Buddha's essentially simple message of personal salvation. The difference is similar to that between Protestants and Catholics at the time of the Reformation in Christianity. Compared to the puritan standards of Theravada Buddhism, the other sect – which later becomes known as Mahayana – introduces a catholic profusion of Buddhist saints.