Prince Su of the First Rank, or simply Prince Su, was the title of a princely peerage used in China during the Manchu-led Qing dynasty. It was also one of the 12 "iron-cap" princely peerages in the Qing dynasty, which meant that the title could be passed down without being downgraded. The first bearer of the title was Hooge, the eldest son of Hong Taiji, the second ruler of the Qing dynasty. He was awarded the title in 1636 by his father. The peerage was renamed to Prince Xian of the First Rank when it was passed on to Hooge's son, Fushou, in 1651. It was also given "iron-cap" status later on. In 1778, when Yunzhu was holding the title, the Qianlong Emperor renamed it back to "Prince Su of the First Rank". The peerage was passed down over ten generations and held by 11 persons – eight as Prince Su, and three as Prince Xian.
Members of the Prince Su / Prince Xian peerage
Hooge, Hong Taiji's eldest son, held the title Prince Su of the First Rank from 1636 to 1648, posthumously honoured as Prince Suwu of the First Rank
*4Fushou, held the title Prince Xian of the First Rank from 1651 to 1669, posthumously honoured as Prince Xianque of the First Rank
**4Danzhen, held the title Prince Xian of the First Rank from 1670 to 1702, posthumously honoured as Prince Xianmi of the First Rank
***2 Chengxin, posthumously honoured as Prince Su of the First Rank. He used to be a supporter general.
****5Yongxi, held the title Prince Su of the First Rank from 1778 to 1821, posthumously honoured as Prince Sugong of the First Rank
*****1Jingmin, held the title Prince Su of the First Rank from 1821 to 1852, posthumously honoured as Prince Sushen of the First Rank
******3Huafeng, held the title Prince Su of the First Rank from 1853 to 1869, posthumously honoured as Prince Suke of the First Rank
*******3Longqin, held the title Prince Su of the First Rank from 1870 to 1898, posthumously honoured as Prince Suliang of the First Rank
********1Shanqi, held the title Prince Su of the First Rank from 1898 to 1922, posthumously honoured as Prince Suzhong of the First Rank
*********1Xianzhang, held the title Prince Su of the First Rank from 1922 to 1945
***6Yanhuang, held the title Prince Xian of the First Rank from 1702 to 1771, posthumously honoured as Prince Xianjin of the First Rank
**5 Baichali, posthumously honoured as Prince Xian of the First Rank. He used to be a bulwark general.
***3Yunzhu, initially succeeded his father as a 3rd class suppoter general. He held the title Prince Xian of the First Rank from 1772 to 1778, had his title renamed to Prince Su of the First Rank in 1778, posthumously honoured as Prince Suqin of the First Rank