During the Tang Dynasty, there lived a man named Chunyu Fen, who was known for his love of wine and his carefree, unrestrained nature. One day, after a heavy drinking session, he fell asleep under a large locust tree. In his dream, he was invited to the kingdom of the Great Locust Tree, where he married a princess and became the governor of a prosperous region. He enjoyed great success and honor for many years, but eventually, his kingdom faced a military defeat, his wife died, and he was dismissed from his post. Waking up in a cold sweat, Chunyu Fen realized that the entire grand kingdom was nothing more than an ant colony beneath the locust tree. This story reminds us that life's greatest triumphs and tragedies can be as fleeting as a dream, urging us to keep our ambitions grounded in reality.
On his birthday, Chun Yufen hosted a feast under the locust tree before his gate, drinking heavily with friends until utterly drunk, and was helped to a corridor to nap. Half-asleep, he saw two purple-clad messengers inviting him into a carriage, which sped toward a tree hole beneath the great locust. Inside, the sun shone bright on a bustling world; after traveling dozens of li, they reached a vermilion gate with a golden plaque reading "Great Locust Peace Kingdom." A prime minister greeted him, announcing the king wished to marry his daughter to Chun Yufen. Overwhelmed, Chun Yufen found himself wed to the Golden Branch Princess and appointed Governor of Nanke Commandery.
Chunyu Fen governed Nanke Commandery with diligence and compassion for twenty years, earning the emperor's favor and the people's devotion. With five sons, two daughters, a prestigious official rank, and a happy family, he felt immensely proud and content.
Unexpectedly, the Kingdom of Sandalwood Vine launched a sudden invasion. Chun Yufen led his troops to resist but suffered repeated defeats; worse still, Princess Golden Branch fell ill and died. Struck by one misfortune after another, Chun Yufen resigned as governor and escorted her coffin back to the capital, losing the king's favor from then on. Gloomy and disheartened, he was granted permission by the king to return to his hometown for a visit, still escorted by the same two envoys in purple.
When Chunyu Fen's carriage emerged from the cave, the familiar hills and rivers of home greeted him. Returning to his house, he was startled to see his own body still lying asleep under the porch. Jolted awake, he found his servant sweeping the courtyard, two friends washing their feet nearby, and the setting sun's glow still lingering on the wall—yet the dream had felt like an entire lifetime.
Chunyu Fen told everyone about his dream, and they were all astonished. Together they searched under the great locust tree and indeed dug up a huge ant nest, with a tunnel leading to a southern branch and another small ant hole. So the "Southern Branch Prefecture" and "Locust Peace Kingdom" in his dream were nothing more than this!
Later, the idiom "A Dream of Southern Branch" came to be used to describe worldly glory and wealth as nothing but an empty dream. Today, it often refers to a fleeting joy that turns out to be hollow.
Source: Li Gongzuo (Tang Dynasty), *Governor of the Southern Branch*
Meaning of the Idiom: Later, the Chinese idiom "南柯一梦" came to describe worldly glory and wealth as nothing but an empty dream.