Gautama was born between 563 BCE and 480 BCE in Nepal. He was born as a Kshatriya, a Hindu.
He grew up in Kapilavastu. Siddhartha was destined by birth to the life of a prince. His father was a king who shielded him from religious teachings and from knowledge of human suffering. His father raised him in great luxury. At the age of 16, his father arranged his marriage to a cousin.
The prince reached the age of 29 with no experience of life outside the wall. He decided to leave his palace and saw a sick man, an old man and a corpse. After that he saw a wandering ascetic.
Gautama realized that he doesn't want to live the life of a prince anymore. He left the palace, shaved his head and put on a beggar's robe. He began his quest for enlightenment.
Renowned teachers taught Siddhartha about the many religious philosophies as well as how to meditate. After that he and five disciplines went to find enlightenment by themselves. They attempted to find release from suffering through physical discipline. Gautama realized that the key to enlightenment wasn't renouncing pleasure, it was the discipline of mind. He had to build up his strength for the effort, and started accepting food.
Siddhartha settled into meditation beneath a fig tree. He came a mythological battle in his mind against a demon called Mara. When the morning came, he realized enlightenment and became a Buddha.
At first Buddha refused to teach anyone, but eventually he held his first sermon to the five companions who had abandoned him. He devoted himself to teaching and gained hundreds of followers. He prescribed a path of practice through which people can realize enlightenment for themselves.
At the age of 80, the Buddha entered Nirvana and left his physical body behind. He abandoned the endless cycle of rebirth and death.
Buddhism has several holy books and texts, but the most important ones are stored in the Tripitaka, also known as the Pali Canon. It's the traditional term for the Buddhist scriptures. Tripitaka is written in an ancient Indian language, Pali, by Buddhist monks. They remembered the teachings orally, but decided to write them down in books, because of the threat of war. The Tripitaka has three parts, Vinaya, Sutta and Abhidhamma. Vinaya contains multiple rules and regulations of monastic life. All of Buddha's sermons are collected in Sutta. The psychological and philosophical discourse is stored in Abhidhamma. It's also holding the interpretation of Buddhism.
It's possible that around 300 BCE, the first westerns would have converted to Buddhism.
The existing Mahayana sutras were composed in the 1st century BCE - 2nd century CE.
The Buddhavacana was written around 29 BCE, but took its present form around 500 CE.
The original Chinese canon of Buddhism was written. A modern version was published in the 20th century.
The Tibetan Buddhist canon was finally composed during this time by Buton Rinchen Drub.
Buddhist modernism is one of the main movements in Buddhism. Its doctrines and teachings differ from the mainstream traditions and it has deemphasized the traditional rituals, cosmology etc. It was emerged in the late-end of the 19th century.
The monks started teaching Buddhism to westerns in the end of the 19th century, first mainly in North America.
The first Buddhist temple in Europe was founded in 1924 in Berlin.
A socio-political movement, The Dalit Buddhist movement, was formed by Dalits in India in 1956. It radically reinterpreted Buddhism. The Dalit Buddhist movement also created a new sect called Navayana. It was started by B. R. Ambedkar when nearly half a million Dalits joined him and created the movement.
The American Buddhist movement was organized in 1960. It promotes Buddhism through publications, ordination of classes, and monks. It doesn't follow any particular school of Buddhism. It was created by American Buddhism practitioners, who thought that the old cultural forms of Buddhism don't have to be followed by the westerns.
Buddhism is being practiced in Europe, America and Australia with increasing numbers.