Li Chengqian

Posthumous name
	Prince Min of Hengshan (恆山愍王)

Li Chengqian
Li Chengqian
Prince Min of Hengshan; 恆山愍王
Crown Prince of the Tang dynasty
Reign	September 626-April 643
Born	619
Died	5 January 645 (aged 25–26)
Spouse	Lady Su (m.9 February 635; elder sister of Su Gui (苏瓌), eldest daughter of Su Dan (苏亶) and great-granddaughter of Su Wei).)
Issue	Li Xiang (李象; father of Li Shizhi); Li Jue
Posthumous name
Posthumous name
	Prince Min of Hengshan (恆山愍王)
Father	Emperor Taizong of Tang
Mother	Empress Zhangsun

Li Chéngqián (李承乾) (619 – 5 January 645^[6]), courtesy name Gaoming (高明), formally Prince Min of Hengshan (恆山愍王), was a crown prince of the Chinese Tang dynasty. He was Emperor Taizong's oldest son and first crown prince, but was replaced later by his younger brother Li Zhi (the eventual Emperor Gaozong).

Li Chengqian was created crown prince in 626 at the age of eight (by East Asian reckoning), after his father became emperor on 4 September.^[7] In his youth, he had a reputation for good judgment, but was also said to be suffering from a foot illness. Later on, he was said to be frivolous, favoring Tujue customs instead of studying about ways to rule an empire. He lost favor in Emperor Taizong's eyes to a younger brother, Li Tai the Prince of Wei. (Both had the same mother, Emperor Taizong's wife Empress Zhangsun.) In 643, in fear that Emperor Taizong was about to depose him in favor of Li Tai, he plotted with the general Hou Junji to overthrow Emperor Taizong. The plot was discovered, and he was deposed and reduced to commoner rank, but Emperor Taizong, believing that Li Tai to be responsible for Li Chengqian's downfall, appointed yet another son, Li Zhi (also by Empress Zhangsun), crown prince instead. Li Chengqian was exiled, and died in exile in January 645, as a commoner under house arrest. He was posthumously granted an imperial prince title during the reign of his grandnephew, Emperor Xuanzong after his grandson Li Shizhi became chancellor.

^ Li Chengqian's tablet indicate that Lady Su was her father's third daughter (妃苏氏祔焉，礼也。妃即隋仆射邳国公威之曾孙、鸿胪卿夔之孙、皇朝沁州刺史亶之第三女也。)
^ (惟尔秘书丞苏亶长女，族茂冠冕，庆成礼训，贞顺自然，言容有则。作合春宫，实协三善，曰嫔守器，式昌万叶。备兹令典，抑惟国章。是用命尔为皇太子妃。往，钦哉！其光膺徽命，可不慎欤！) Quan Tang Wen, vol.09
^ ([贞观]九年正月甲申，皇太子承乾納妃蘇氏，宴羣臣賜帛各有差。) Cefu Yuangui, vol.80
^ (苏瓌，字昌容，京兆武功人，隋尚书右僕射威曾孙也。祖夔，隋鸿胪卿。父亶，贞观中台州刺史。) Jiu Tang Shu, vol.88.
^ Li Chengqian's biography in vol.80 of New Book of Tang lists his title as "Prince Min of Changshan" (常山湣王).
^ Volume 197 of Zizhi Tongjian recorded that Li Chengqian died on the renyin day of the 12th month of the 18th year of the Zhenguan era of Tang Taizong's reign. This date corresponds to 5 Jan 645 on the Julian calendar. [(贞观十八年)十二月，...壬寅，故太子承乾卒于黔州,...]. This date was also found in Taizong's biography in New Book of Tang. Taizong's biography in Old Book of Tang dated Chengqian's death to the xinchou day of the same month and year, which corresponds to 4 Jan 645 in the Julian calendar. However, his epitaph (唐故恒山愍王墓志铭) recorded a markedly different death date: the 1st day of the 10th month of the 17th year of the Zhenguan era, which corresponds to 17 Nov 643 in the Julian calendar.
^ Volume 191 of Zizhi Tongjian recorded that Taizong assumed the throne on the jiazi day of the 8th month of the 9th year of the Wude era of Tang Gaozu's reign. This date corresponds to 4 Sep 626 on the Gregorian calendar. [(武德九年八月)甲子，太宗即皇帝位于东宫显德殿...] Li's biographies in volume 76 of Old Book of Tang and volume 80 of New Book of Tang recorded that he was made crown prince when Taizong became emperor.

[1] Li Chengqian's tablet indicate that Lady Su was her father's third daughter (妃苏氏祔焉，礼也。妃即隋仆射邳国公威之曾孙、鸿胪卿夔之孙、皇朝沁州刺史亶之第三女也。)

[2] (惟尔秘书丞苏亶长女，族茂冠冕，庆成礼训，贞顺自然，言容有则。作合春宫，实协三善，曰嫔守器，式昌万叶。备兹令典，抑惟国章。是用命尔为皇太子妃。往，钦哉！其光膺徽命，可不慎欤！) Quan Tang Wen, vol.09

[3] ([贞观]九年正月甲申，皇太子承乾納妃蘇氏，宴羣臣賜帛各有差。) Cefu Yuangui, vol.80

[4] (苏瓌，字昌容，京兆武功人，隋尚书右僕射威曾孙也。祖夔，隋鸿胪卿。父亶，贞观中台州刺史。) Jiu Tang Shu, vol.88.

[5] Li Chengqian's biography in vol.80 of New Book of Tang lists his title as "Prince Min of Changshan" (常山湣王).

[6] Volume 197 of Zizhi Tongjian recorded that Li Chengqian died on the renyin day of the 12th month of the 18th year of the Zhenguan era of Tang Taizong's reign. This date corresponds to 5 Jan 645 on the Julian calendar. [(贞观十八年)十二月，...壬寅，故太子承乾卒于黔州,...]. This date was also found in Taizong's biography in New Book of Tang. Taizong's biography in Old Book of Tang dated Chengqian's death to the xinchou day of the same month and year, which corresponds to 4 Jan 645 in the Julian calendar. However, his epitaph (唐故恒山愍王墓志铭) recorded a markedly different death date: the 1st day of the 10th month of the 17th year of the Zhenguan era, which corresponds to 17 Nov 643 in the Julian calendar.

[7] Volume 191 of Zizhi Tongjian recorded that Taizong assumed the throne on the jiazi day of the 8th month of the 9th year of the Wude era of Tang Gaozu's reign. This date corresponds to 4 Sep 626 on the Gregorian calendar. [(武德九年八月)甲子，太宗即皇帝位于东宫显德殿...] Li's biographies in volume 76 of Old Book of Tang and volume 80 of New Book of Tang recorded that he was made crown prince when Taizong became emperor.

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