Temple titles (miaohao 庙号) were accorded to deceased emperors for use at ancestral sacrifices. This practice is believed to have originated in the Shang Dynasty. The last character of such names were customarily zu (祖 progenitor) or zong (宗 ancestor). The temple names were given according to strict rules. Those with great achievements would have names ending with zu and those of high virtue would have zong. For instance, the founder of a dynasty could be named taizu (太祖) or taizong (太宗), and someone with outstanding achievements might be named gaozu (高祖) or gaozong (高宗). Like the bestowal of posthumous names to emperors, the use of temple titles was an important political tradition in Chinese culture. By honoring past emperors, they provided a standard for later generations of rulers to follow. Due to Chinese influence, Korea and Vietnam used to follow this practice.

In ancient times,emperors were given temple titles, so that later rulers can learn their great achievements and high virtue. This practice began in the three dynasties of Xia, Shang and Zhou and continued in the Western and Eastern Han dynasties. Emperors of this period deserved their temple titles, since they did make great achievement and have high virtue.That's why this practice has been adopted by later dynasties.  (Liu Zhiji: All About Historiography)