The temple name is the name given to the ancient Chinese emperor when he was enshrined in the Ancestral Temple after his death.
It is generally believed that temple names originated from the Shang Dynasty, such as Taijia as Taizong, Taiwu as Zhongzong, and Wuding as Gaozong (Chengtang may be Taizu). Temple titles were initially very strict. According to the standard of "the ancestors have merit and the clan has virtues," the founding monarch is generally the ancestor and successor monarch who have the ability to govern the country.
The Zhou Dynasty established the posthumous title system and gave final evaluations to the life deeds of monarchs and ministers. The temple number system was abolished. In the Qin Dynasty, even the posthumous title system was abolished.
Extended information:
Temple names are the names given to emperors in East Asia when they are enshrined in temples. They originated from the Shang Dynasty, which valued sacrifice and worship.
Before the Sui Dynasty, not all kings had temple names. Generally, after the death of a king, a dedicated family temple would be built to offer sacrifices. However, after a few generations, the original temple would have to be destroyed and the sacrifices would be merged with the Imperial Ancestral Temple. It is called "祧" for worshiping in the Imperial Ancestral Temple, and the "祧" thing has a practical effect.
If every king’s temple is left behind, there will be difficulties in performing sacrifices in numerous family temples after several generations. The ancestors who have made great contributions to the country and are worthy of eternal sacrifice by their descendants will specially bear the temple name to show their intention to erect a temple for sacrifice forever.
Baidu Encyclopedia-Temple Number