Shakyamuni or Tathagata are different names by which Lord Buddha was known in Buddhist literature. The Buddhism, a new religion, was founded in the 6th century BC with attainment of 'enlightenment' in Bodh Gaya and delivery of 'first sermon' in Sarnath near Varanasi. Born as Siddhartha (family name Gautam) to Shakya ruler Shuddhodhana and Queen Maya, in Lumbini on Vaishakh Purnima, Gautam married Yashodhara and had a son Rahul. Contrary to indulgence in the royal luxury, Gautam remained perturbed with the signs of sickness, old age and death that he observed in the worldly life. The resultant unease drove him at the age of 29 to explore the source and path of peace and understanding of the world's ills. At Bodh Gaya in Bihar, at the age of 35, Gautam or Siddharth got enlightened and re-christened as Buddha. Buddha attained enlightenment on 'Vaishakh Purnima' and thus "Vaishakh Purnima' holds very pious place in Buddhism. After getting 'enlightened', Buddha delivered his first sermon in Sarnath, near Varanasi, in front of his 5 disciples. After more than 40 years of wandering about giving discourses and spreading his spiritual thought, the Buddha attained 'mahaparinirvana' at Kushinara (now in Uttar Pradesh).
The governing philosophy of Buddhism centres round 'middle path' i.e. avoidance of the extremes of life like utter indulgence in worldly pleasure, unbearable asceticism and self-mortification. Buddhism does not delve into tangible or intangible creator of the universe. Buddhism concentrates more on find out reasons of sorrow and pain and its solution. Buddhism centres round Four Noble Truths and Eightfold Paths to address those four noble truths. Four Noble Truths are- the existence of suffering ('dukkh'); suffering is caused by 'trishna'; suffering can be mitigated and removed, there is a path that leads to the cessation of suffering. The Eightfold Paths, called 'Ashtangik Marg' and aimed at alleviating sufferings, are (i) right speech, kind and truthful; (ii) right action, honest and peaceful; (iii) right livelihood without hurting any living being; (iv) right effort involving self-control; (v) right mindfulness; (vi) right concentration and meditation on the meaning of life; (vii) right thoughts worthy of the sincere and intelligent man; and (viii) right understanding, avoiding superstition.
Buddhism flourished in India to an extent but it expanded more across Indian borders. Several kings, prominently Ashok and Harshvardhana, patronized Buddhism as state religion. Indian culture got a fresh impetus from Buddhism in the intellectual, literary, artistic and architectural fields. Indeed, the missionaries of Buddhism spread India's culture beyond its boundaries to Myanmar (Burma), Sri Lanka, China, Laos, Thailand and other places.
In the 6th century BC, about the same time as Mahavira, Prince Siddhartha, who later came to be known as the Buddha, revolted against the religion as practiced in his day. Like Mahavira, he renounced the world and discovered that "kama" (desire) lay at the root of all evil. The cessation of desire he found possible only through knowledge. In the ideal state of existence, there is a release from the cycle of births and rebirths and this is called "nirvana". In this state, the ego of man is completely annihilated and he is free from joys and sorrows alike.
From India, the country of its origin, Buddhism spread to other parts of the world. It found a large following in the countries of eastern and south-eastern Asia.