Gautama is the key figure in Buddhism, and accounts of his life, discourses, and monastic rules were summarized after his death and memorized by the sangha. Passed down by oral tradition, the Tripitaka was committed to writing about four hundred years later. Hindus regard Gautama as an avatar of Lord Vishnu. Few of the details of the Buddha's life can be independently verified, and it is difficult to determine what is history and what is myth. Therefore this article will describe the life of Siddhartha Gautama as told in the earliest available Buddhist texts.

Conception and birth
Siddhartha Gautama was born in Lumbini that was a part of ancient Indian Sakya Kingdom and is now situated in modern Nepal, under the full moon of the sixth lunar month, in the spring. His father was Suddhodana, a King among the Kshatriya caste. His mother was Maya Devi, one of Suddhodana's wives. The day of the Buddha's birth is widely celebrated in Buddhist countries as Vesak. Gautama was born a prince, destined to a life of luxury.

According to legend, before his birth Gautama had visited his mother during a vision, taking the form of a white elephant. During the birth celebrations, a seer announced that this baby would either become a great king or a great holy man. His father, King Suddhodana, wishing for Gautama to be a great king, shielded his son from religious teachings or knowledge of human suffering.

Marriage
When the young Prince Siddhartha Gautama was still a baby, an ascetic named Kaladevala went into the heaven of the 33 Gods of the Vedas, and predicted that the young prince would become the Buddha. As the boy reached the age of 16, his father arranged his marriage to Yashodhara, a cousin of the same age. In time, she gave birth to a son, Rahula. Gautama lived up to the age of 29 as a prince in Kapilavastu, a place situated now in Nepal. Although his father ensured that Gautama was provided with everything he could want or need, Gautama was constantly troubled and internally dissatisfied.

The Great Departure
In venturing outside of his palace, Gautama saw an old crippled man (old age), a diseased man (illness), a decaying corpse (death), and an ascetic. These four scenes are referred to as the four sights. Gautama was inspired by these sights - he sought to overcome old age, illness, and death by living the life of an ascetic. Gautama soon left his home, his possessions, and his family at age 29, to take up the life of a wandering monk.

Abandoning his inheritance, he dedicated his life to learning how to overcome suffering. He pursued the paths of Yoga and meditated with two Brahmin hermits, and although he achieved high levels of meditative consciousness, he was not satisfied with this path. Gautama then chose the robes of a mendicant monk and headed to north-east India. He began training in the ascetic life and practicing vigorous techniques of physical and mental austerity. Gautama proved adept at these practices, and was able to surpass his teachers.

However, he found no answer to his questions. Leaving behind his teachers, he and a small group of companions set out to take their austerities even further. Gautama attempted to find enlightenment through complete deprivation of worldly goods, including food, and became a complete ascetic. After nearly starving himself to death (some sources claim that he nearly drowned), Gautama began to reconsider his path. Then he remembered a moment in childhood in which he had been watching his father start the season's plowing, and he had fallen into a naturally concentrated and focused state which was blissful and refreshing.

After leaving
After discarding asceticism and concentrating on meditation, Gautama discovered what Buddhists call the Middle Way—a path of moderation away from the extremes of self-indulgence and self-mortification. He accepted a little buttermilk from a passing goatherder, Sumedha. Then, sitting under a pipal tree, now known as the Bodhi tree, he vowed never to arise until he had found the Truth. At the age of 35, he attained Enlightenment; according to some traditions, this occurred approximately in May, and according to others in December. Gautama, from then on, was known as "The Perfectly Self-Awakened One", the Sammasambuddha.

He stated that he had realized complete Awakening and insight into the nature and cause of human suffering, along with steps necessary to eliminate it. These truths were then categorized into the Four Noble Truths; the state of supreme liberation—possible for any being—was called Nirvana.

According to one of the stories in the Ayacana Sutta (Samyutta Nikaya VI.1), a scripture found in the Pcli and other canons, immediately after his Enlightenment, the Buddha was wondering whether or not he should teach the Dharma. He was concerned that, as human beings were overpowered by greed, hatred and delusion, they would not be able to see the true dhamma which was subtle, deep and hard to understand. However, a spirit, Brahma Sahampati, interceded and asked that he teach the dharma to the world, as "there will be those who will understand the Dharma". With his great compassion, the Buddha agreed to become a teacher.

At the Deer Park near Benares in northern India he set in motion the Wheel of Dhamma by delivering his first sermon to the group of five companions with whom he had previously sought enlightenment. They, together with the Buddha, formed the first Sangha, the company of Buddhist monks.

The Buddha emphasized that he was not a god, he was simply enlightened. He stated that there is no intermediary between mankind and the divine; distant gods are subjected to karma themselves in decaying heavens; and the Buddha is solely a guide and teacher for the sentient beings who must tread the path of Nibbana themselves to attain spiritual awakening and see truth and reality as it is. The Buddhist system of insight, thought, and meditation practice was not revealed divinely, but by the understanding of the true nature of the mind, which could be discovered by anybody.

For the remaining 45 years of his life, the Buddha traveled in the Gangetic Plain of Northeastern India, teaching his doctrine and discipline to an extremely diverse range of people— from nobles to street outcaste sweepers, including many adherents of rival philosophies and religions. The Buddha founded the community of Buddhist monks and nuns (the Sangha) to continue the dispensation after his Parinibbana or complete Nibbana, and made thousands of converts. His religion was open to all races and classes and had no caste structure. On the other hand, Buddhist texts record that he was reluctant to ordain women as nuns: he eventually accepted them on the grounds that their capacity for enlightenment was equal to that of men (and the Lotus Sutra, in Chapter 12, contains a description of the dragon king's daughter attaining enlightenment in her present body), but he gave them certain additional rules (Vinaya) to follow.

The Great Passing
The death of the Buddha, or parinirvana, Gandhara 2-3rd century.
At the age of eighty, the Buddha ate his last meal, which, according to different translations, was either a mushroom delicacy or soft pork, which he had received as an offering from a blacksmith named Cunda. Falling violently ill, possibly from mesenteric infarction, the Buddha realized that his end was approaching fast. He told his attendant Ananda to prepare a bed between two Sal trees at Kushinagar, and then finally passed away. The Buddha's final words were, "All composite things pass away. Strive for your own salvation with diligence."

The Buddha's body was cremated and the relics were placed in monuments or stupas, some of which are believed to have survived until the present.

Personality and character
The Buddha as presented in the Buddhist scriptures is notable for such characteristics as:

A comprehensive education and training in those fields appropriate to a warrior aristocrat, such as martial arts, agricultural management, and literature, and also a deep understanding of the religious and philosophical ideas of his culture.
Athletic and fit throughout his life, competent in martial arts such as chariot combat, wrestling, and archery, and later easily hiking miles each day and camping in the wilderness. (Images of a fat "Jolly Buddha" or Laughing Buddha are actually depictions of either Maitreya, The future Buddha, or a 10th century Chinese monk, sometimes called Hotei, Hoti, or Milefo.)
A superb teacher, with a fine grasp of the appropriate metaphors, and tailoring his teachings to the audience at hand.
Fearless and unworried at all times, whether dealing with religious debators, royalty, or murderous outlaws. He was never past exasperation when monks of his order misrepresented his teachings.

Temperate in all bodily appetites. He lived a completely celibate life from age 29 until his death. He was indifferent to hunger and environmental conditions.

Physical characteristics
Buddha is perhaps one of the few sages for whom we have mention of his rather impressive physical characteristics. He was at least six feet tall and had a strong enough body to be noticed by one of the Kings and was asked to join his army as a general. Although the Buddha was not represented in human form until around the 1st century CE, his physical characteristics are described in one of the central texts of the traditional Pali canon, the Digha Nikaya. They help define the global aspect of the historical Buddha, his physical appearance is described by Buddha's wife to his son Rahula upon Buddha's return in the scripture of the "Lion of Men":

1. Like the full moon is His face; He is dear to Gods and men; He is like an elephant amongst men; His gait is graceful as that of an elephant of noble breed. That, indeed, is your father, lion of men.

2. He is of Aryan (aristocratic nobility) lineage, sprung from the warrior caste; His feet have been honoured by Gods and men; His mind is well established in morality and concentration. That, indeed, is your father, lion of men.

3. Long and prominent is His well-formed nose, His eye-lashes are like those of a heifer; His eyes are extremely blue ; like a rainbow are His deep blue eyebrows. (The word used is "adhi nila", meaning "very blue", nila is used for the word blue sapphire.) That, indeed, is your father, lion of men.

4. Round and smooth is His well-formed neck; His jaw is like that of a lion; His body is like that of king of beast; His beautiful skin is of bright golden colour. That, indeed is your father, lion of men.

Interpretations may vary, and the reliability of the Sutras may be questioned. The description above is indicative of a typically Indo-Aryan body type. This can also be related to the tradition describing the historic Buddha as a member of the Indian Kshatriya warrior caste.

Teachings
The teachings of the Buddha are covered in the articles on Buddhism and Buddhist philosophy. Many Buddhist sects disagree as to what the Buddha actually taught. There seems to be major agreement on these points:

The Four Noble Truths: that suffering is an inherent part of existence; that suffering is caused by attachment(craving); that craving can be ceased; and that following the Eightfold Path will lead to the cessation of craving (and suffering).
The Noble Eightfold Path: right understanding, right thought, right speech, right action, right livelihood, right effort, right mindfulness, and right concentration.

The law of dependent causation: that events are not predestined, nor are they random, but that events are caused by the actions that preceded them.

Rejection of the infallibility of accepted scripture: teachings should not be accepted unless they are borne out by our experiences.

Anicca (pronounce as "anatesa"): That all things are impermanent.

Anatta: That the perception of a constant "self" is an illusion.

Buddha as viewed by other religions

Bahá'í Faith
Bahá'ís believe that Buddha was a "Manifestation of God," or one in a line of prophets who have revealed the Word of God progressively for a gradually maturing humanity. In this way, Buddha shares an exalted station with Abraham, Moses, Zoroaster, Krishna, Jesus, Muhammad, the Báb, and the founder of the Bahá'í Faith, Bahá'u'lláh. However, the Central Figures of the Bahá'í Faith caution believers that, as is the case with many Manifestations, it is difficult to say which Buddhist teachings that have come down through history are authentic and which have been corrupted. Abdul Bahá, one of the Central Figures, said, "The founder of Buddhism was a wonderful soul. He established the Oneness of God, but later the original principles of His doctrines gradually disappeared, and ignorant customs and ceremonials arose and increased until they finally ended in the worship of statues and images." (Some Answered Questions, p. 165)

Hinduism
Some Hindu denominations regard Buddha as the ninth avatar of Lord Vishnu. Buddhists in general do not consider the Buddha to be God or an avatar of any god. The general decline of Buddhism in India has been attributed to the development of Vedanta philosophy which began challenging Buddhism's philosophically strong image.

Islam
Some Muslims believe that Siddharta Gautama is the same person who is referred to in the Koran as Dhul-Kifl, and that he was therefore a prophet of Islam. The meaning of Dhul-Kifl is unclear, but, according to this view, it means "the man from Kifl", where Kifl is the Arabic pronunciation of Kapilavastu, where the Buddha spent thirty years of his life. More common views, however, hold that Dhul-Kifl was a different person and not a prophet at all, or that he was the prophet called Ezekiel in the Bible.

Christianity
The legend of "Barlaam and Josaphat", written down by St. John of Damascus some time around the 7th century, bears a close resemblance to the story of the Buddha. Barlaam and Josaphat found their way into the Roman Martyrology (27 November), and into the Greek calendar (26 August).