Siddhartha Gautama was born in present-day Nepal into a royal family. As a prince, Siddhartha was raised in luxury and was well taken care of for his entire life. He met a woman he loved and married her and had a child. When he was 29-years-old, Siddhartha looked around him and saw the suffering of the world. It was unacceptable to him that there was so much suffering, and he immediately set out on a quest to end the suffering of mankind.
For six years Siddhartha wandered around and tried to find the answer. In the town of Uruvela, Siddhartha eventually stopped his wandering and sat down underneath a tree. He decided that he was going to sit under the tree until he had found the answer of how to end the world's suffering. After a time he was able to achieve enlightenment.
After reaching enlightenment, Siddhartha sat and looked at the tree for seven days, and then embarked on a walking meditation. There is a stupa built in the place where he sat, it is called the Animeschalochana Stupa. The path where he went on that walk is known as the Jewel Walk. Soon after, Siddhartha went around and taught what he had learned. His first teaching was the Four Noble Truths. For 40 years Siddhartha, who was then called Shakyamuni, taught those who lived in the Ganges Valley about Buddhism.
The tree that Siddhartha Gautama sat under that day was called a bodhi tree. A bodhi tree is a type of fig tree named, Ficus religiosa. A branch of the bodhi tree was taken to Sri Lanka by King Asoka's daughter and that tree still grows there. There is still a bodhi tree in the same spot as where he sat, although it is a descendant of that original tree. The bodhi tree that stands in the spot now was planted in 1881 by a British Archaeologist. Today, many people come to see and touch that bodhi tree on a yearly pilgrimage, to be in the place where Buddhism first began.
The bodhi tree is located at Bodh Gaya. The first bodhi tree was destroyed in the 2nd Century BC by King Puspyamitra. The tree planted to replace the original tree was planted in the 7th Century AD.