Siddhartha was born a prince in Nepal around 563 B.C. His father met with a fortune teller and the fortune teller told his father that Siddhartha would either be a great ruler or a religious leader. Siddhartha's father wants him to be a ruler.
Siddhartha with his begging bowl.
Siddhartha was born living a life of luxury without pain or sadness. He never saw anyone experiencing either of those feelings. Siddhartha married at a young age and had a baby. The whole court celebrated this.
Siddhartha in self-denial
A couple of times when Siddhartha was 29 and riding outside the castle by himself without guards he saw four horrors. The four horrors he saw were: a man leaning on a stick, a man shrunk by disease, a man who had died, and a man with barely anything (but he was happy). After that he proclaimed that all joy died within him. Then he became an minimalist.
Siddhartha deep in meditation under a fig tree.
Because Siddhartha saw these four horrors he decided to search for truth about life, death, and suffering. He lived on food that strangers placed in his begging bowl. Through this he learned that salvation is possible so he joined a group of ascetics after he gained no head way with gurus.
For Siddhartha, self-denial was denial of physical comfort. He barley ate anything. He was living on one jujube fruit and one grain of rice a day. He fainted from so little food so he quit self-denial and ate food which annoyed his fellow ascetics.
After Siddhartha quit self-denial he meditated under a fig tree for 49 days with the goal of becoming enlightened. The god Mara tried to stop his meditating with promises of wealth, and when that didn't work, he tried to attack Siddhartha. Finally, Siddhartha was enlightened so he saw his past lives just as he left his life of desire and he achieved salvation. Then he returned to earth to teach others how to reach salvation.