Emperor Yao Di had a habit of touring his kingdom with the company of his administration and observed the need of his people. One day, he came to the Xuan Yuan Mountain of I County (Anhui) and was tired. Yao fell asleep and had a dream. He dreamt of Emperor Huang Di playing a game of Weiqi against a fairy Yong Cheng. Yao had never seen this game before. Huang Di explained to him that he invented this game in preparation for a battle against the fierce tribal leader Chi You. Black and white stones represent soldiers from both sides. With this game, Huang Di defeated Chi You. Yao asked Huang Di to teach him the game. After he woke up, Yao reconstructed the rules based on his memory. Because of this, Zhang Hua of Han Dynasty wrote in Bowuzhi, 'Yao created Weiqi'. Dan Zhu was the son of Yao's concubine San Yi. After Yao grew up, he loved to play and had no interest in studying. To enlighten Dan Zhu, Yao taught Dan Zhu Weiqi. Due to Dan Zhu's playful nature, he was quick in learning the game and soon beat his father. Zhang Hua recorded in Bowuzhi, 'Dan Zhu was great in Weiqi.' Unfortunately, Dan has no interest in anything else besides Weiqi. When Yao was advanced in age he decided to elect a Tiandi Official to replace Yihe. His followers recommended Dan Zhu but Yau disagreed, stating that Dan was no good in anything else other than Weiqi. Yao appointed Shun as his successor, giving his two daughters to Shun as wives. Eventually Dan Zhu was exiled to Yan (Yan Zhu Cheng of Shandong).