Siddhartha Gautama was born into a royal family. His father was king. A fortune teller predicted that Sid would have two futures. They were to become a king or to become a religious leader. Sid's father wanted him to become a king.
The Hindu Gurus
Sid's father wanted to protect Sid. He made sure of this by sending guards out to make sure all of the sick, poor, or sad people were out of the way when Sid was riding in his chariot. He didn't want Sid to see these types of people.
Give up your search. You can have gold and wealth if you give up.
The Bodhi Tree
Even if my blood shall run dry, I will not leave this seat until truth has been realized.
Ahh... I finally see now. I understand. I am enlightened.
Sid got married. When he was about 29 years old, he went out by himself without his guards. He saw four sick, poor, holy, and sad people. The prince realized that as people get older, they die. They were called the four passing sights.
These are the ideas of Buddhism...
Sid goes out into the forest to do something about this. He meets the Hindu gurus, but realizes that their way of life is not for him. He keeps on searching and comes across the Ascetics. The Ascetics don't eat much, so when Sid ate more than he was "supposed" to, they abandoned him.
Siddhartha Gautama continued his search. He meditated under a Bodhi Tree for 49 days. He was visited by Mara who told him to give up, but he did not. Sid saw his past lives and understood what happened after death. Siddhartha entered a state of perfect wisdom or enlightenment. Siddhartha Gautama then became the Buddha.
Buddha then traveled all over India and taught his beliefs for 45 years. Everyone would always ask him if he was a god, angel, or a saint. His answer was always, I am awake. Buddha trained people to be teachers. Buddha's purpose was to awaken the world to the true nature of life. Buddha's life ended when he was 80 years old.