The eighth son of the Kangxi Emperor, Yunsi was a pivotal figure in the power struggle over the succession to his father's throne.

However, towards the later years of the emperor's reign, Yinreng engaged in increasingly licentious activities and also established a strong political base revolving around his own authority, causing him to rapidly lose favour.

In 1708, during a hunting trip to Rehe, the Kangxi Emperor grew suspicious that the crown prince was conspiring to oust him in a coup.

Four days later, in an apparent sign of trust, the Kangxi Emperor commissioned Yinsi to oversee the imperial household department to 'clean house' and remove some vestiges of Yinreng's influence.

Yinzhi, seeing his own hopes of attaining the crown prince position evaporate, gave his backing to Yinsi, who had been raised in the household of his mother.

In response, the emperor, rather than rewarding Yinsi, sentenced Zhang to death by lingchi in order to discourage others from becoming involved in the struggle for succession.

[6] The Kangxi Emperor, disillusioned by ambitions of his remaining sons and the ferocity with which they were plotting against one another, reinstated Yinreng in the crown prince position in 1709.

In what became essentially a straw-poll vote, the majority of court officials petitioned to the Kangxi Emperor that Yinsi should assume the position of Crown Prince.

In 1724, for example, the emperor ordered Yunsi to kneel in the inner reaches of the Forbidden City for an entire night, ostensibly for an infraction committed during his oversight of the Lifan Yuan.

[8] But according to Hei tu dang (黑图档), a Manchu script document now kept in Liaoning Provincial Museum, the original term is "Akina" (ᠠᡴᡳᠨᠠ).

Its interior structure was altered shortly after Yunsi's expulsion from the imperial clan in 1725, and converted to a storehouse during the reign of the Qianlong Emperor.

Its approximate location is near the present-day Wangfujing Station of the Beijing Subway, near the Ministry of Commerce of the People's Republic of China.