Mooncakes, originally came from the food used by Tang Dynasty army to celebrate military victories. During the reign of Emperor Gaozu of Tang, General Li Jing successfully quelled a rebellion by the Huns and returned triumphantly on the 15th day of the eighth lunar month.
At that time, a merchant from Turpan offered a cake to the Tang emperor in celebration of the victory. Emperor Gaozu, upon receiving the beautifully decorated cake box, took out the round cake and pointing to the bright moon in the sky, said with a smile: "We should invite the toad (referring to the moon) with this Hu-style cake." He then shared the cake with his ministers.
Mooncakes symbolize reunion and are a must-have delicacy during the Mid-Autumn Festival. On the festival night, people also enjoy eating watermelon, fruits, and other round-shaped fruits, praying for a happy, sweet, and peaceful family life.
There are several other stories about mooncakes: One says that after Chang'e flew to the moon, she entrusted a dream to her husband Houyi, asking him to make rice flour balls on the night of August 15, as round as the moon, and burn incense in prayer, hoping for the reunion of the couple.
Another story goes that during the Tang Dynasty, Emperor Taizong Li Shimin sent General Li Jing to personally lead troops to fight against the northern Turkic invasions. After many battles along the frontier, they achieved remarkable victories. On the 15th day of the eighth lunar month, they triumphantly returned to the capital. To celebrate the victory, the city of Chang'an was filled with fireworks and music, and the soldiers and civilians celebrated all night long. At that time, a Tibetan merchant specially presented the emperor with mooncakes to celebrate the victory. Emperor Taizong was delighted, took out the colorful round cakes from the elaborately decorated cake box, and pointed to the bright moon hanging in the sky, saying: "We should invite the moon palace (i.e., the moon) with this Hu-style cake." Then, he distributed the mooncakes to his civil and military officials. From then on, the custom of eating mooncakes during the Mid-Autumn Festival spread.
Another story tells that during the Song Dynasty, there was a small sweet cake which Su Dongpo tasted and praised with a poem: "Small cakes like chewing the moon, with su (a kind of pastry filling) and sweetness inside." People then began to call these small cakes "mooncakes."
Yet another story suggests that at the end of the Yuan Dynasty, due to political corruption and oppressive officials, the common people suffered greatly. At that time, Zhu Yuanzhang and Liu Bowen organized a peasant uprising, writing the time of the uprising on small pieces of paper and hiding them inside small cakes. On the night of the Mid-Autumn Festival, when families ate the small cakes, they found the notes and thus joined the uprising. The small sweet cakes were later named mooncakes in memory of this action.