Yao, a legendary ruler with the personal name of "Fangxun' in ancient Chinese mythology, was the son of Emperor Ku and Qingdu, the emperor's third concubine surnamed Chenfeng. Yao was also named "Yaotang Shi" and widely known as "Tangyao", due to the land conferred upon him in Yao and Tang areas. At the age of 15, Yao began to assist his elder brother Emperor Zhi in ruling the country. Thanks to his high moral standards, his reputation spread far and wide and vassals all pledged allegiance to him. In the end, Emperor Zhi gave the throne to Yao out of admiration for his ethics and talent. After ascending the throne, Yao was given the title "Emperor Yao". During his reigning period, Emperor Yao put lots of outstanding people in important positions and made remarkable political achievements. He ordered Xi and He to formulate the calendar system and sent Gun and Yu to control floods to keep disaster away from the people. He also launched punitive expeditions against barbarian tribes and banished evil doers and criminals. With him at the helm, the people enjoyed a good and prosperous life. In his later years, Yao handed over the crown to Shun, who had exceptional talent and moral virtues. It is said that when Yao died, all the people grieved as if they had lost their parents. For three years, music and recreational activities were banned as a way to pay tribute to the great man.

In Chinese accounts of the beginning of their civilization, three rulers of exceptional virtue followed the legendary culture heroes Fuxi (Fu-hsi), Shengnong (Shengnung), and the Yellow Emperor; they were Kings Yao, Shun, and Yu. Their shared characteristic was that each rejected his own son as unworthy and tried to install the best-qualified man as his successor, unsuccessfully in the case of Yu. Their unselfishness has figured importantly in Chinese historical writings and made them model rulers. Documents that purportedly date to their rule constitute the first section of the second Confucian classic, the Shu Jing (Shu Ching), or Book of History (also called Book of Documents). Yao (r. 2357–2256 b.c.e.) and Shun (r. 2255–2205 b.c.e.) are revered figures because they epitomized wisdom, humility, and unselfishness. The canon of Yao in the Book of History cites Yao as a descendant of the Yellow Emperor and credits him with devising a calendar of 356 days to regulate agriculture, encouraging morality, establishing a rudimentary government, and above all selecting a successor unselfishly. After ruling for 70 years he set about choosing a worthy successor because he thought his own son unfit and found a humble man called Shun, who was admired as a dutiful son to undeserving parents. Shun did not think himself worthy, but Yao insisted and married his two daughters to Shun to observe his behavior. Yao shared his rule with Shun for 28 years and then abdicated in favor of Shun. Shun, according to legend, also descended from the Yellow Emperor and was a virtuous and benevolent ruler. Both Yao’s and Shun’s reigns were troubled by great floods and attempts to build dikes that did not work. Shun then appointed an official named Yu to deal with the problem. Yu traveled the land and worked on flood control for more than a decade, succeeding because he dredged the riverbeds and channeled the water to the sea. He worked so hard that on three occasions he passed his own house and heard his wife and children weeping in loneliness but did not go in. Such was his dedication that Shun set aside his son, made Yu his co-ruler for 17 years, and then abdicated in his favor. Yu was also a humane and wise ruler (r. 2205– 2198 b.c.e.). Together Yao, Shun, and Yu are called the Three Sage Rulers. Yu also attempted to bypass his son and appoint the best man his successor. The people were so grateful to him that they insisted on putting his son Qi (Chi) on the throne. Thus began the first Chinese dynasty, the Xia (Hsia) dynasty. The territory under these three rulers was centered on modern Shanxi (Shansi) Province in northern China. Later, Chinese historians idealized Yao, Shun, and Yu, extolling their reign as the golden age. Their moral conduct became the grand themes of historical and literary writings for posterity. As a result of modern scientific methods of investigating history they have been assigned to the position of legendary figures.

Yao 堯 was one the mythical Five Emperors (wudi 五帝). Some sources render his personal name as Yi Qi 伊祁 or Yi Fangxun 伊放勳. He is first mentioned in the books Guoyu 國語 and Zuozhuan 左傳 and also in the Chuci 楚辭 poems, as a wise ruler who did not inherit his throne to his own son, but ceded it (chanrang 禪讓) to the worthiest, Shun 舜. His position in the hierarchy of tribal ancestors seemed not to have been very high, because the title Di Yao 帝堯 "Divine Ancestor Yao" only appears as late as in the book Shanhaijing 山海經. His deification took place under the influence of Confucians and Mohists that both venerated him as a sage-ruler with high moral standars. Yet the veneration of him goes back to the Yaodian 堯典 "Canon of Yao" that is part of the Shangshu 尚書, where Yao is praised as an example of political virtuousness. Contrary to this image, the Zhushu jinian 竹書紀年 says that Yao encarcerated Shun and usurped his throne. In the Shiben 世本 genealogies, Yao is mentioned as the third son of Di Ku 帝嚳, a great-grandson of the Yellow Emperor (Huang Di 黃帝). These genealogies also mention his tribal name (shi 氏) as Tao Tang 陶唐, Tang Yao 唐堯, or simply Tang 唐. To complicate matters further, the Lüshi chunqiu 呂氏春秋 lists Tao Tang before the Yellow Emperor, while Yao is in the third position after the Yellow Emperor, so that it becomes clear that both can not be identical. The famous history Shiji 史記 names him Tang Yao 唐堯. He is said to have been the son of Di Ku and a younger brother of Emperor Zhi 摯 and followed the latter to the throne, when Zhi abdicated in favour to him. His first residence was Jifang 冀方 (modern Tangxian 唐縣, Hebei), yet he moved later to Jinyang 晉陽 (modern Taiyuan 太原, Shanxi) and then to Pingyang 平陽 (modern Linfen 臨汾, Shanxi). The apocryphal classic Chunqiu hecheng tu 春秋合誠圖 (quoted in the history Yishi 繹史) says that Yao's mother Qingdu 慶都 was born in the wilderness of Douwei 斗維 in the far south. The was impregnated by a red dragon (chilong 赤龍) and gave birth to Yao in Danling 丹陵. During the 70 years long rule of Yao over an empire that covered the same area as modern China (as stated in the Hanfeizi 韩非子), wonderful animals came to light to express his wonderful and selfless virtue. Yao's own appearance was also very strange. He had eight-coloured eyebrows and deep eyeholes. A story narrated in the Lunheng 論衡 goes that once ten suns rose and threatened to burn the whole earth. Yao therepon took bow and arrows and shot down nine of the suns. This story has also been told in the Huainanzi 淮南子, where the wonderful archer was Yi 羿, who acted on the order of Yao. Yao's ministers Xi 羲 and He 和 made calendric calculations and created the oldest Chinese calendar (see Xi He 羲和). Yao was married to Nü Huang 女皇, the daughter of Lord San Yi 散宜氏. She gave birth to Zhu Dan 丹朱, according to other legends to nine sons, but all of them proved morally not good enough to succeed him to the throne. He therefore asked the tribesleaders of the Four Summits (siyue 四岳, i.e. of the four regions) whom he should nominate as his successor, and they suggested to virtuous Shun.