Mid-Autumn Festival

Origin
The custom of worshipping the moon (called Xi yue in Chinese) for both the Han and minority nationalities, can be traced as far back as the ancient Xia, and Shang Dynasties (2000 BCE-1066 BCE). In the Zhou Dynasty (1066 BCE-221 BCE), the people celebrated the Mid-Autumn Festival to worship the moon.
The practice became very prevalent in the Tang Dynasty (618-907 CE) that people enjoyed and worshipped the full moon. In the Southern Song Dynasty (1127-1279), however, people started making round moon cakes, as gifts to their relatives in expression of their best wishes of family reunion. At night, they came out to watch the full moon to celebrate the festival. Since the Ming (1368-1644), and Qing Dynasties (1644-1911), the custom of Mid-Autumn Festival celebration has become unprecedentedly popular

Stories of the Mid-Autumn Festival
Hou Yì and Chang'e

While Westerners may talk about the "man in the moon", the Chinese talk about the "woman on the moon". The story of Chang E, and her flight to the moon, is familiar to every Chinese, and a favourite subject of poets. Unlike many lunar deities in other cultures who personify the moon, Chang'e only lives on the moon. Tradition places Hou Yì and Chang'e around 2170 BC, in the reign of the legendary Emperor Yao, shortly after that of Huang Di.
There are so many variations of the Chang'e legend that one can become overwhelmed and utterly confused. However, most legends about Chang'e in Chinese mythology involve some variation of the following elements: Hou Yì, the Archer; Chang'e, the mythical Moon Goddess of Immortality; an emperor, either benevolent or malevolent; an elixir of life; and the Moon:


Hou Yì, the archer
There are at least four variations to this story where Hou Yì was an archer.

Version 1: Hou Yì was himself an immortal, while Chang'e was a beautiful young girl, working in the Jade Emperor's (Emperor of Heaven) Palace as the attendant to the Queen Mother of the West (wife of the Jade Emperor), before her marriage. One day, Yì aroused the jealousy of the other immortals, who then slandered him before the Jade Emperor. Yì and his wife, Chang'e, were subsequently banished from heaven, and forced to live by hunting on earth. He became a famous archer.
Now at this time, there were 10 suns that took turns to circle the earth ? one every 10 days. One day, all 10 of the suns circled together, causing the earth to scorch. Emperor Yao, the Emperor of China, commanded Yì to kill all but one of the suns. Upon the completion of his task, the Emperor rewarded Yì with a pill, the elixir of life, and advised him: "Make no haste to swallow this pill, but first prepare yourself with prayer and fasting for a year". Yì took the pill home and hid it under a rafter, while he began healing his spirit. In the midst of this, Yì was summoned again by the emperor. While he was gone, Chang'e noticed a white beam of light beckoning from the rafter and discovered the pill, which she swallowed. Immediately, she found that she could fly. Just at that moment, Yì returned home, and realizing what had happened, began to reprimand her. Chang'e flew out the window into the sky.
With bow in hand, Yì sped after her, and the pursuit continued halfway across the heavens. Finally, Yì had to return to the Earth because of the force of the wind. Chang'e reached the moon, and breathless, she coughed. Part of the pill fell out from her mouth. Now, the hare was already on the moon, and Chang'e commanded the animal to make a pill from it, so that she could return to earth to her husband.
As of today, the hare is still pounding. As for Yì, he built himself a palace in the sun as "Yang" (the male principle), while Chang'e is "Yin" (the female principle). Once a year, on the 15th day of the full moon, Yì visits his wife. That is why the moon is full and beautiful on that night. [1]
This description appears in written form in two Western Han dynasty (206 BCE-24 CE) collections; Shanhaijing (Classic of the Mountains and Seas, a book of travels and tales), and Huainanzi (scientific, historical and philosophical articles, named for the Prince of Huai).

Version 2: Another version, very similar to the above story, had it that the Emperor of Heaven, moved by the people’s suffering caused by the 10 scorching suns, sent the archer, Prince Hou Yì, from heaven to help Emperor Yao bring order. Hou Yi, with his wife, Chang'e, descended to earth, carrying a red bow and white arrows given him by the Emperor of Heaven.

Version 3: The earth once had ten suns circling over it, each taking turn to illuminate the earth. One day, however, all ten suns appeared together, scorching the earth with their heat. Hou Yi, a strong and tyrannical archer, saved the earth by shooting down nine of the suns. He eventually became King, but grew to become a despot.
One day, Yi stole the elixir of life from a goddess. However, his beautiful wife, Chang'e, drank it in order to save the people from the her husband’s tyrannical rule. After drinking it, she found herself floating, and flew to the moon. Yi loved his divinely beautiful wife so much, he did not shoot down the moon.

Version 4: Another version, however, had it that Chang'e and Hou Yi were immortals living in heaven. One day, the ten sons of the Jade Emperor transformed into ten suns, causing the earth to scorch. Having failed to order his sons to stop ruining the earth, the Jade Emperor summoned Yi for help. Yi, using his legendary archery skills, shot down nine of the sons, but spared one son to be the sun. The Jade Emperor was obviously displeased with Yi’s solution to save the earth. As punishment, he banished Yi and Chang'e to live as mere mortals on earth.
Seeing that Chang'e felt extremely miserable over her loss of immortality, Yi decided to journey on a long, perilous quest to find the pill of immortality so that the couple could be immortals again. At the end of his quest, he met the Queen Mother of the West, who agreed to give him the pill, but warned him that each person would only need half a pill to regain immortality.
Yi brought the pill home and stored it in a case. He warned Chang'e not to open the case, and then left home for a while. Like Pandora in Greek mythology, Chang'e became curious. She opened up the case and found the pill, just as Yi was returning home. Nervous that Yi would catch her, discovering the contents of the case, she accidentally swallowed the entire pill, and started to float into the sky because of the overdose. Although Yi wanted to shoot her in order to prevent her from floating further, he could not bear to aim the arrow at her. Chang'e kept on floating until she landed on the moon.
While she became lonely on the moon without her husband, she did have company. A jade rabbit, who manufactured elixirs, also lived on the moon.