Son of heaven

The Son of Heaven (Chinese and Japanese: 天子; pinyin: Tiānzǐ; ) is an imperial title originating from the ancient Han Chinese emperors and subsequently adopted by other East Asian monarchs that was founded on the theoretical principle of the cosmic Mandate of Heaven. The Son of Heaven is a universal emperor who rules tianxia comprising "all under heaven" which translates from the ancient Chinese into English as "ruler of the whole world." The title was interpreted literally only in China and Japan, and the Chinese and Japanese monarchs were referred to as a demigod, deity or "living God" chosen by the cosmic intelligence or entity referred to as the "Heavens" which in ancient Chinese sources usually referred to the universe.

The title Son of Heaven comes from the Mandate of Heaven, created by the monarchs of the Zhou dynasty to justify deposing the Shang dynasty. They declared that Heaven had revoked the mandate from the Shang and given it to the Zhou in retaliation for Shang corruption and misrule. Heaven bestowed the mandate to whomever was best fit to rule. The title held the emperor responsible for the prosperity and security of his people through the threat of losing the mandate.

The ancient Han Chinese imperial title of tianzi (天子^?) was later adopted by the Emperor of Japan during the Asuka period. Japan sent diplomatic missions to China, then under the rule of the Sui dynasty, forming cultural and commercial ties. The Yamato state modeled their government after the Confucian imperial bureaucracy. A mission in 607 delivered a message that greeted the Sui emperor by saying that "the Son of Heaven in the land where the sun rises ... to the Son of Heaven in the land where the sun sets." The Japanese title was less conditional than its Chinese counterpart. There was no divine mandate that punished the emperor for failing to rule justly. The right to rule of the Japanese emperor, descended from the sun goddess Amaterasu, was absolute.

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