Fu Kang 'an was the only prince in the Qing Dynasty. Fu Kang 'an was raised in the harem by Qianlong from an early age. After he became an adult, Qianlong sealed him thirteen times, but he didn't betroth the princess to him. Because Emperor Qianlong gave Fu Kang 'an all kinds of special treatment, later generations speculated that Fu Kang 'an might be the illegitimate child of Emperor Qianlong.

Fu Kang 'an is the son of Fu Heng and the nephew of the Queen Ganlong Fucha. Therefore, Fu Kang 'an often went in and out of the palace since he was a child, perhaps because Fu Kang 'an was clever since he was a child, perhaps because he was the nephew of Empress Fucha. In a word, Emperor Qianlong loved Fu Kang 'an very much, so he kept Fu Kang 'an in his palace and received education with the princes.

Because Fu Kangan grew up in the palace and was personally educated by Emperor Qianlong, the relationship between Emperor Qianlong and Fu Kangan was very good. Some unpopular princes are not as high as Fu Kang 'an. At that time, Fu Kang 'an was just an adult. In order to give Fu Kang 'an military power, Emperor Qianlong was afraid that Fu Kang 'an would participate in the Jinchuan rebellion on the border. At that time, the commander-in-chief of the Qing army was A Gui, and A Gui fought many battles. When Fu Kang 'an went to the front, A Gui had basically calmed the border. At that time, Fu Kang 'an went to the border to wait for the troops to return to the DPRK and was rewarded with a seal.

Fu Kang 'an, who was so loved by Emperor Qianlong, did not become Xu of the Qing Dynasty like his brother. Later, after Fu Kang 'an put down the rebels, Emperor Qianlong made Fu Kang 'an his concubine. At that time, in addition to the royal family, officials with other names could not be knighted. This shows how high Fu Kang 'an is in the heart of Emperor Qianlong, so future generations will speculate that Fu Kang 'an may be the illegitimate child of Emperor Qianlong.