Gautama Siddhartha was born near Lumbini, on the borders of modern day India and Nepal, around 566 BCE. His father was Suddhodana, king of the Sakyas. His mother was Mahamaya. He emerged painlessly and cleanly from Queen Maya’s right side as she was strolling through the garden in Lumbini. She was standing, and supported herself on the branch of a fig tree. He could walk immediately, and took seven steps in each of the four directions, symbolising he practised the Four Immeasurables. Wherever his feet touched the ground, lotuses sprouted. He announced in a clear voice that this would be his last birth.

This event is celebrated on the 7th day of the 4th month of the Tibetan calendar. 

Siddhartha’s abilities quickly impressed his teachers and he rapidly learnt a wide range of subjects, including languages and mathematics. He also became proficient in sports like wrestling and archery. He excelled in all things, surpassing his fellow pupils, and even going beyond what his teachers could teach him. He was tall, strong and handsome, and his good manners and kindness endeared him to everyone. Siddhartha was brought up with all the luxuries of royalty. 

Prince Siddhartha leaves the palace at the age of 29. The king tried to prevent this, and was deeply distressed. Siddhartha agreed to stay and rule the kingdom provided his father would grant him four wishes. They were: that old age would never assail him; that he would remain in perpetual good health free from disease; that he would be made immortal so death would never haunt him; that he would always be wealthy and subject to no misfortune. The king, of course, was powerless to grant these requests.

Siddhartha wandered as an ascetic, begging for his food. He studied with leading Vedantic teachers and mastered all they had to teach, but he left them because he found that their teachings were not able to cut the root of desire.
Then he engaged in harsh mortification of the body for six years. 

However, he found that none of these practices enabled him to attain Nirvana. One day he collapsed and was found by a shepherd who gave him milk. The renewed strength of his body is actually helpful to his mind, so he abandons asceticism as a path.

He went to a nearby river called Naranjara to bathe himself. He then returned to the bank and began his last meal as an aspirant to Buddhahood. The meal over, he washed his hands and the bowl, and placed the bowl on the water to float. Then he said: “If today I am to attain full enlightenment, may this golden bowl swim upstream.” The bowl immediately did so.

He then made a seat and sat under the Bodhi Tree to meditate. 

Mara is the lord of the realm of desire. If he is defeated, all the gods and demons of the desire realms are subdued as well. Mara’s army has magical powers and uses all kinds of weapons. Shakyamuni remains unshaken. When they throw weapons at him they transform into flowers. Mara changes tactic and sends his daughters to seduce Shakyamuni. They use all sorts of feminine wiles but Shakyamuni remains unshaken. When Mara’s daughters fail to move Shakyamuni, his army comes back and throws more weapons, which again transform into flowers. Why do they transform into flowers? Because Shakyamuni recognizes the demons and their weapons as interdependent and empty in nature. Finally the battle is over, and Mara is defeated. 

At the age of 35, Shakyamuni becomes fully enlightened. This is celebrated on the full moon day of the fourth month of the Tibetan calendar, Saga Dawa Düchen.

“At that moment none gave way to anger, no one was ill or experienced any discomfort, none resorted to sinful ways or indulged in intoxication of mind; the world became tranquil, as though it had reached perfection.” (Buddhacarita xiv.90)

The Buddha remained seated under the Bodhi tree for seven days after his enlightenment, without blinking. 

The first turning took place in the Deer Park at Sarnath, Varanasi where Buddha taught the Four Noble Truths. It is mainly concerned with abandoning negative actions of the body, speech and mind.

The second turning on the absence of characteristics took place on Vulture’s Peak Mountain in Rajagriha. It is primarily about abandoning clinging to the self of individual and of phenomena.

The third turning on the complete revelation took place in Vaishali and other places. The third turning is about abandoning clinging to emptiness. 

Six rains after his enlightenment, the Buddha ascended to the Heaven of Thirty Three to give teachings to his mother. This is the uppermost terrestrial heaven, and is located on the peak of Mount Meru. This is when he opened the Abhidharma teachings. He spent three months there, and descended back to the human realm on the day celebrated as Lha Bab duchen on the 22nd day of the ninth month of the Tibetan calendar.

The Abhidharma comprises the philosophical teachings of Buddhism, which constitute the third Pitaka or Basket of teachings. 

The first fifteen days of the Tibetan lunar year celebrate the fifteen days on which, in order to increase the merit and aid the devotion of future disciples, Buddha displayed a different miracle each day.

The fifteenth day of the first month, the full moon day, is celebrated as Chotrul Düchen. On this day the effects of positive or negative actions are multiplied 10 million times. 

The final passing beyond suffering manifested by buddhas and highly realized masters at the end of their lives. Passing into parnirvana is the twelfth of the twelve deeds of a buddha. Shakyamuni Buddha demonstrated passing into parinirvana at the age of eighty in the town of Kushinagara around 486 BCE.

He became absorbed in meditation and finally passed into Parinirvana. At that moment, there was an earthquake, “the earth trembled, the stars shot from the heavens, and in the ten quarters of the sky there burst forth flames and the sounds of celestial music.”

This is comemorated on Saga Dawa Düchen, the full moon day of the 4th month in the Tibetan calendar.