Temple names are posthumous titles accorded to monarchs of the Sinosphere for the purpose of ancestor worship.
[1] The practice of honoring monarchs with temple names began during the Shang dynasty in China and had since been adopted by other dynastic regimes in the Sinosphere, with the notable exception of Japan.
In earlier times, temple names were exclusively assigned to competent rulers after their death.
Initially, in deciding whether a monarch should be honored as "祖" (zǔ; "progenitor") or "宗" (zōng; "ancestor"), a principle was strictly adhered to: "祖" was to be given to accomplished rulers while "宗" was to be assigned to virtuous rulers.
However, this principle was effectively abandoned during the Sixteen Kingdoms era with the ubiquitous usage of "祖" by various non-Han regimes.
The practice of honoring rulers with temple names had since been adopted by other dynastic regimes within the East Asian cultural sphere|Sinosphere, including those based on the Korean Peninsula and in Vietnam.