What is "zhenjin"

Zhenjin (; 1243 – January 5, 1286), also ' Jingim', Chinkim, or Chingkim , was the second son of Kublai Khan, founder of the Yuan dynasty. He was designated as the Crown Prince by Kublai Khan in 1273, and became the head of the Central Secretariat (Zhongshu Sheng). The North Chinese Buddhist monk Haiyun gave him the name Zhenjin (True Gold) when he was born in 1243. He was also known as a strong supporter of Confucianism. When a Confucian-trained official in the South proposed that Kublai abdicate in favor of Zhenjin in 1285, Kublai was angered. Zhenjin died on 5 January 1286, 8 years before his father Kublai Khan. Distressed by his death, Kublai Khan made Zhenjin's son Temür the new Crown Prince, who later became the Temür Khan or Emperor Chengzong.