Dan, Duke Wen of Zhou (), commonly known as the Duke of Zhou (), was a member of the royal family of the early Zhou dynasty who played a major role in consolidating the kingdom established by his elder brother King Wu. He was renowned for acting as a capable and loyal regent for his young nephew King Cheng, and for successfully suppressing the Rebellion of the Three Guards and establishing firm rule of the Zhou dynasty over eastern China. He is also a Chinese culture hero credited with writing the I Ching and the Book of Poetry, and establishing the Rites of Zhou. Life His personal name was Dan (). He was the fourth son of King Wen of Zhou and Queen Tai Si. His eldest brother Bo Yikao predeceased their father (supposedly a victim of cannibalism); the second-eldest defeated the Shang Dynasty at the Battle of Muye around 1046 BC, ascending the throne as King Wu. King Wu distributed many fiefs to his relatives and followers and Dan received the ancestral territory of Zhou near present-day Luoyang. Only three years after assuming power, King Wu died and left the kingdom to his young son King Cheng. The Duke of Zhou successfully attained the regency and administered the kingdom himself, leading to revolts not only from disgruntled Shang partisans but also from his own relatives, particularly his older brother Guan Shu. Within five years, the Duke of Zhou had managed to defeat the Three Guards and other rebellions and his armies pushed east, bringing more land under Zhou control. The Duke of Zhou was credited with elaborating the doctrine of the Mandate of Heaven, which countered Shang propaganda that as descendants of the god Shangdi they should be restored to power. According to this doctrine, Shang injustice and decadence had so grossly offended Heaven that Heaven had removed their authority and commanded the reluctant Zhou to replace the Shang and restore order. On a more practical level, the Duke of Zhou expanded and codified his brother's feudal system, granting titles to loyal Shang clansmen and even establishing a new holy city at Chengzhou around 1038 BC. Laid out according to exact geomantic principles, Chengzhou was the home of King Cheng, the Shang nobility, and the nine tripod cauldrons symbolic of imperial rule, while the Duke continued to administer the kingdom from the former capital of Haojing. Once Cheng came