Xuanwu () or Xuandi (), also known as Zhenwu (真武, True Warrior) or Zhenwudadi (真武大帝, True Martial Great Emperor), is a revered deity in Chinese religion, one of the higher-ranking deities in Taoism. He is revered as a powerful god, able to control the elements and capable of great magic. He is identified as the god of the north Heidi (黑帝 , Black Emperor and is particularly revered by martial artists. He is the patron god of Hebei, Henan, Manchuria and Mongolia. As some Han Chinese (now the modern-day Cantonese and Fujianese peoples) migrated into the south from Hebei and Henan during the Tang-Song era, Xuanwu is also widely revered in the Guangdong, Guangxi and Fujian provinces, as well as among the overseas diaspora.
Since the usurping Yongle Emperor of the Ming dynasty claimed to receive the divine assistance of Xuanwu during his successful Jingnan Campaign against his nephew, he had a number of Taoist monasteries constructed in the Wudang Mountains of Hubei, where Xuanwu allegedly attained immortality.
Black Tortoise
Xuanwu is one of the Four Symbols of the Chinese constellations, representing the north and the winter season. It is usually depicted as a turtle entwined together with a snake.
One story says that Xuanwu was originally a prince of Jing Le State in northern Hebei during the time of the Yellow Emperor. As he grew up, he felt the sorrow and pain of the life of ordinary people and wanted to retire to a remote mountain for cultivation of the Tao.
Another says that Xuanwu was originally a butcher who had killed many animals mercilessly. Yet as time passed, his conscience grew and he felt remorse for his actions. Upon repenting, he abandoned butchery and retired to a remote mountain for cultivation of the Tao.
One day, after assisting a woman in labor, as he cleaned her blood stained clothes in a river nearby, the words "Dark (or Mysterious) Heavenly Highest Deity" (玄天上帝 Xuántiān Shàngdì) appeared before him. The woman in labor was a manifestation of the goddess Guanyin.