Zhu Biao (10 October 1355 – 17 May 1392) was the eldest son of the Hongwu Emperor, the founder of the Ming dynasty. Upon the establishment of the Ming dynasty in 1368, Zhu Biao was appointed as crown prince. In order to prepare for his future reign, he received a comprehensive Confucian education. However, he died at the young age of thirty-eight in 1392, during his father's lifetime. He was succeeded by his eldest surviving son, Zhu Yunwen, who ascended the throne six years later as the Jianwen Emperor.

Zhu Biao was born in Taiping (present-day Anhui), the seat of Zhu Yuanzhang at the time, and was his first son. In 1364, when his father declared himself King of Wu, he named Zhu Biao as his heir. After Zhu Yuanzhang proclaimed himself emperor of the Ming dynasty, Zhu Biao was given the title of crown prince (皇太子, huang taizi). He received an intensive education in Confucian teachings under the guidance of Song Lian and grew up to be an educated and humane politician, similar in these qualities to his mother.^[1] From 1377, he actively participated in the emperor's meetings with ministers and played a role in the day-to-day management of the state.^[1]

Zhu Biao's first wife was the daughter of Chang Yuchun. They married in 1371 and had two sons, Zhu Xiongying (1374–1382) and Zhu Yuntong (1377–1417).^[1] His second wife was the daughter of Lü Ben (吕本; d. 1382), a Yuan official who had joined Zhu Yuanzhang early in his rise. They had three sons, Zhu Yunwen (the Jianwen Emperor), Zhu Yunjian (d. 1402), and Zhu Yunxi (1391–1406).^[1]

In September 1391, Zhu Biao was sent to inspect the province of Shaanxi with the task of considering moving the capital to Chang'an (present-day Xi'an).^[1] He returned from his journey at the end of the year, but before any measures could be taken, he fell ill in January 1392 and died a few months later.^[1] He was buried in a mausoleum at the foot of Zhong Mountain on the outskirts of Nanjing.

After his death, his eldest son Zhu Yunwen became the crown prince and posthumously named him emperor after ascending the throne. However, the third Ming emperor, the Yongle Emperor, overthrew the Jianwen Emperor and abolished the imperial status of Zhu Biao.^[2][1] It was not until two centuries later, in 1644, that Zhu Biao was once again posthumously promoted to emperor.^[3][c]

After his first son, Zhu Xiongying, Zhu Biao followed the practice of including a generation name into the personal names of his other children. The names followed a generation poem:^[4]

允文、遵祖訓。

欽武、大君勝。
順道、宜逢吉。

師良、善用晟。

This poem was intended to govern the first character of the personal names of the next twenty emperors of the Ming dynasty. However, only the first two were officially used. After the usurpation of the Prince of Yan, the Jianwen Emperor was said to have died in a fire. His surviving children were either killed or kept in isolation to prevent rivals from taking the throne. Similarly, the younger sons of Zhu Biao were also kept under house arrest or killed. However, during the Republic of China, politician Wang Pixu (王丕煦) wrote a county chronicle for Laiyang, in which he recorded that Zhu Yuntong had many descendants there through his son Zhu Wenkun (朱文坤).^[5]

Consorts and Issue:

• Empress Xiaokang, of the Chang clan (孝康皇后 常氏; 1355–1378)
  • Zhu Xiongying, Prince Huai of Yu (虞懷王 朱雄英; 1 December 1374 – 12 June 1382), first son
  • Zhu Yuntong, Prince Dao of Wu (吳悼王 朱允熥; 29 November 1378 – 1 September 1417), third son
• Crown Princess Yiwen, of the Lü clan (懿文皇太子妃 呂氏; 1359–1412)
  • Zhu Yunwen, the Jianwen Emperor (建文帝 朱允炆; b. 5 December 1377), second son
  • Zhu Yunjian, Prince Min of Heng (衡愍王 朱允熞; 27 July 1385 – 1402), fourth son
  • Zhu Yunxi, Prince Jian of Xu (徐簡王 朱允熙; 13 July 1391 – 3 February 1407), fifth son
• Unknown
  • Princess Jiangdu (江都郡主), first daughter
    • Married Geng Xuan (耿璿), the first son of Geng Bingwen, in 1394
  • Princess Yilun (宜倫郡主), second daughter
    • Married Yu Li (於禮) in 1417
  • Third daughter
  • Princess Nanping (南平郡主; d. 1412), fourth daughter