Tianzi 天子 "Son of Heaven" was an official title of the sovereign through the history of China. It ended with the founding of the Republic in 1911.
Kingship has often a sacred character (divine right), but in China and some other East Asian countries, the ruler was regarded formally as an offspring of Heaven (tian 天). This concept begins during the Shang period 商 (17th-11th cent. BCE) with the function of the sovereign as a medium, shaman or priest (wu 巫, zhu 祝 "supplicator", bu 卜 "diviner") between worldly matters and supernatural powers in the shape of ancestral spirits or universal spirits like "Heaven". The king communicated with them by various means, be it dances, prayers, or divinations. There was no separation between the secular and the sacred realm in oldest times.
The court of the Zhou dynasty 周 (11th cent.-221 BCE) included quite a few functionaries entrusted with sacral matters, like the Minister of Rites (dazongbo 大宗伯, functions described in the ritual Classic Zhouli 周禮) who was responsible for the arrangement of religious rituals like sacrifices, ritual announcements, incantations (zhou 咒) or prayers of petition (qi 祈). It might be that even persons usually perceived as secular leaders like the Duke of Zhou 周公 served also in religious positions (Ching 1997: 7).
Out of the shamanic tradition, the king of Zhou was seen as a person having privileged access to the gods and spirits and could therefore mediate between the latter and the human beings. The loneliness in the exercise of this specific power is expressed in early Zhou terms like "Me, the one man" (yiren 一人), "Me, the childish one", (tong 侗), or "Me, the lonely one" (gu 孤). The usual character for the Chinese word for the "king" (wang 王) is variously identified as the image of an axe symbolizing the royal power, a fire in the earth, or, from the Han period 漢 (206 BCE-220 CE) on, as a person establishing a 'vertical' link 丨 between the trinity 三 of Heaven, Earth, and Man (Ching 1997: 14-15). Another term for the sovereign is "Son of Heaven". It appears in texts of the Classic Shangshu 尚書, and in bronze inscriptions. The king is granted the right to rule by the Heavenly Mandate (tianming 天命), which is connected to the condition of rule by virtue instead of by sheer power.
Heaven itself is seen as an anthropomorphic being, as can be seen in the character 天, being a highlighting of the head or utmost part of a person's 人 body. "August Heaven" (huangtian 皇天) was the place were the Supreme Deity (shangdi 上帝, see Shang religion) was residing. The combination of huang 皇 and di 帝 was the term by which the king of Qin 秦, having unified China under his rule as the First Emperor of Qin 秦始皇帝 (r. 246-210 BCE), wanted to establish an ever-lasting dynasty. The words huang and di are also used for the mythological emperors of remote antiquity (sanhuang wudi 三皇五帝).
The Confucians saw the rule of a king as the normal, justified way of government by virtue—the "royal way" (wangdao 王道), which stood in contrast to rulership by force, as seen in that of the hegemonial rulers (badao 霸道) during the Spring and Autumn period 春秋 (770-5th cent. BCE). The ancient rulers like Yao 堯 and Shun 舜 were perceived as "Sages" (sheng 聖) with much charisma making them the ideal leaders of the people.
The enthronement of a ruler followed strict rituals envolving prayers before the ancestral tablet of the predecessor, sacrifices to various deities and spirits, and the observation of the astral bodies and phenomena in the sky. It also included an inspection tour through the empire. The enthronement ceremony included the recitation of a testamentary charge which ordered ministers and dignitaries to serve the new king loyally, and the king to follow the way of his ancestors in exerting a rule of benevolence and virtue. The king was invested with the help of functionaries like the Grand Protector (taiwei 太尉) who handed over the royal regalia during ceremonies and investitures.
|惟四月哉生魄，王不懌。甲子，王乃洮頮水；相被冕服，憑玉几。乃同召太保奭、芮伯、彤伯、畢公、衛侯、毛公、師氏、虎臣、百尹、御事。||In the fourth month, when the moon began to wane, the sovereign [King Cheng 周成王] was indisposed. On the day jiazi (see calendar), he washed his hands and face; his attendants put on him his cap and robes; (and he sat up), leaning on a gem-adorned bench. He then called together the Grand-Guardian Shi 奭, the earls of Rui 芮 and Tong 彤, the duke of Bi 畢, the marquis of Wei 衛, the duke of Mao 毛, the master of the warders (shishi 師氏), the master of the guards (huchen 虎臣), the heads of the various departments (baiyin 百尹), and the superintendents of affairs (yushi 御事).|
|王曰：「嗚呼！疾大漸，惟幾。病日臻，既彌留，恐不獲誓言嗣，玆予審訓命汝。||The king said, 'Oh! my illness has greatly increased, and it will soon be over with me. The malady comes on daily with more violence, and maintains its hold. I am afraid I may not find (another opportunity) to declare my wishes about my successor, and therefore I (now) lay my charge upon you with special instructions.|
|昔君文王武王宣重光，奠麗陳教，則肄，肄不違，用克達殷集大命。在後之侗，敬迓天威，嗣守文武大訓，無敢昏逾。||The former rulers, our kings Wen 周文王 and Wu 周武王, displayed in succession their equal glory, making sure provision for the support of the people, and setting forth their instructions. (The people) accorded a practical submission, without any opposition, and the influence (of their example and instructions) extended to Yin 殷 (Shang 商), and the great appointment (of Heaven) was secured. After them, I, the stupid one, received with reverence the dread (decree) of Heaven, and continued to keep the great instructions of Wen and Wu, not daring blindly to transgress them.|
|今天降疾、殆，弗興弗悟。爾尚明時朕言，用敬保元子釗，弘濟于艱難。柔遠能邇，安勸小大庶邦。思夫人自亂于威儀，爾無以釗冒貢于非幾。」||Now Heaven has laid affliction on me, and it seems as if I should not again rise or be myself. Do you take clear note of these my words, and in accordance with them watch reverently over my eldest son Zhao 釗, and greatly assist him in the difficulties of his position. Be kind to those who are far off, and help those who are near. Promote the tranquillity of the states, small and great, and encourage them (to well-doing). I think how a man has to govern himself in dignity and with decorum; do not you allow Zhao to proceed heedlessly on the impulse of improper motives.'|
|玆既受命，還，出綴衣于庭。越翼日乙丑，王崩。||Immediately on receiving this charge, (the ministers and others) withdrew. The tent was then carried out into the court; and on the next day, (being) yichou, the king died. [Follows the description of the preparations for the mourning and funeral ceremonies.]|
|王出在應門之內，太保率西方諸侯入應門左，畢公率東方諸侯入應門右，皆布乘黃朱。賓稱奉圭兼幣曰：「一二臣衛，敢執壤奠。」皆再拜稽首。||The king came forth and stood (in the space) within the fourth gate of the palace, when the Grand-Guardian led in the princes of the western regions by the left (half) of the gate, and the duke of Bi those of the eastern regions by the right (half). They then all caused their teams of light bay horses, with their manes and tails dyed red, to be exhibited; and, (as the king's) guests, lifted up their rank-symbols, and (the other) presents (they had brought), saying, 'We your servants, defenders (of the throne), venture to bring the productions of our territories, and lay them here.' (With these words) they all did obeisance twice, laying their heads on the ground. The king, as the righteous successor to the virtue of those who had gone before him, returned their obeisance.|
|王義嗣德荅拜。太保暨芮伯咸進，相揖，皆再拜稽首曰：「敢敬告天子，皇天改大邦殷之命，惟周文武誕受羑若，克恤西土。惟新陟王，畢賞罰，戡定厥功，用敷遺後人休。今王敬之哉。張皇六師。無壞我高祖寡命。」||The Grand-Guardian and the earl of Rui, with all the rest, then advanced and bowed to each other, after which they did obeisance twice, with their heads to the ground, and said, 'O Son of Heaven, we venture respectfully to declare our sentiments. Great Heaven altered its decree which the great House of Yin had received, and Wen and Wu of our Zhou grandly received the same, and carried it out, manifesting their kindly government in the western regions. His recently ascended majesty, rewarding and punishing exactly in accordance with what was right, fully established their achievements, and transmitted this happy state to his successors. Do you, O king, now be reverent. Maintain your armies in great order, and do not allow the rarely equalled appointment of our high ancestors to come to harm.'|
|王若曰：「庶邦侯、甸、男、衛，惟予一人釗報誥。昔君文武丕平富，不務咎，厎至齊信，用昭明于天下。則亦有熊羆之士，不二心之臣，保乂王家，用端命于上帝。皇天用訓厥道，付畀四方，乃命建侯樹屏，在我後之人。||The [new] sovereign [King Kang] spoke to the following effect: 'Ye princes of the various states, chiefs of the hou, dian, nan, and wei domains (see Zhou administration), I, Zhao, the One man, make an announcement in return (for your advice). The former rulers, Wen and Wu, were greatly just and enriched (the people). They did not occupy themselves to find out people's crimes. Pushing to the utmost and maintaining an entire impartiality and sincerity, they became gloriously illustrious all under heaven. Then they had officers brave as bears and grisly bears, and ministers of no double heart, who (helped them) to maintain and regulate the royal House. Thus (did they receive) the true favouring decree from the High Ancestor (shangdi 上帝), and thus did great Heaven approve of their ways, and give them the four quarters (of the land). Then they appointed and set up principalities, and established bulwarks (to the throne), for the sake of us, their successors.|
|今予一二伯父尚胥暨顧，綏爾先公之臣服于先王。雖爾身在外，乃心罔不在王室。用奉恤厥若，無遺鞠子羞。」||Now do ye, my uncles, I pray you, consider with one another, and carry out the service which the dukes, your predecessors, rendered to my predecessors. Though your persons be distant, let your hearts be in the royal House. Enter thus into my anxieties, and act in accordance with them, so that I, the little child, may not be put to shame.'|
Translation by Legge 1865.
In imperial times, the accession to the throne happened in two stages, first the investment as Son of Heaven, and second, the investment as emperor (Ching 1997: 22).
Among the royal regalia of the early kings, the nine tripods or cauldrons (jiuding 九鼎) were most famous. They symbolized the king's authority over the sphere of craftsmanship, the control of economic resources, and his junction with the universe by the symbolic number nine, the highest of the Yang numbers (see Yin and Yang theory), and thus also the realm of divination with the help of numerology. According to legend, they dated from the early Xia period and thus served as symbols of authority not just over generations, but also over dynasties. The nine cauldrons became a booty of the state of Qin in the mid-3rd century and were probably lost in River Si 泗水.
In imperial times, the most imperial regalia were the six state seals (guoxi 國璽).
As Sons of Heaven, the Zhou rulers and their successors in imperial times delivered sacrifices to Heaven and Earth in the suburban sacrifces (jiaosi 郊祀) and the fengshan sacrifices 封禪 on Mt. Taishan. The suburban sacrifices were carried out throughout imperial times and constituted an important aspect of civic or state religion. It was linked with a ceremony making the king or emperor a husbandman by obliging him to plow three furrows in the earth. The fengshan sacrifices were rarely carried out because they required enormous logistic preparations.
As kingship was concerned with sacral and astronomical matters, the governance of the kingdom was subject to sacral geography, and therefore the Zhouli and other ancient texts try to define symbolic boundaries of the king's power. His effective rule required the calculation of the movements of the celestial bodies (see calendar) to predict eclipse and other phenomena, and the establishment of a calendar. His rule was to adapt to the four seasons and eventual changes in the Five Agents (wuxing 五行). In the end, the Zhou king and his imperial successors were symbolically so much integrated into the cosm that one might call him "cosmic man" (Ching 1997: 39), a position in which he had to harmonize Heaven, earth, and man.
While receiving instructions from above, the king himself instructed his dignitaries in the Bright Hall (Mingtang 明堂) and the Biyong Hall 辟雍. Being the Son of Heaven was a heavy burden and not just the advantage of being given political power.