YIN-ssŭ 胤禩, Mar. 29, 1681–1726, Sept. 30, was the eighth son of Emperor Shêng-tsu. His mother (née Wei 衛, title, Liang-fei 良妃, d. 1711), born of a plebian family, entered the Palace as a maid, but before the birth of Yin-ssŭ she was made an imperial consort. In 1698 Yin-ssŭ was made a prince of the third degree and began to assume a position of prominence among the Emperor's sons. When Yin-jêng [q. v.], the Heir Apparent, was deposed in 1708, several of his brothers began to assert their claims to the throne; among them was Yin-ssŭ who, as an active rival, had the support of several brothers and of certain high officials. For having dispatched agents to purchase books in Kiangsu he achieved the reputation of being a scholar. He is said to have held secret interviews with astrologists, physiognomists and other magicians, intending perhaps to solicit their help when necessary. His aggressiveness, however, displeased the Emperor who rebuked him severely for asserting his claims and accused him of being under the domination of his wife, a granddaughter of Yolo [q. v.]. The Emperor deprived Yin-ssŭ for a time of all rank. The latter, however, claimed the support of powerful officials who, when asked to express their opinion in the matter stood wholeheartedly for Yin-ssů. So great was their influence, especially that of Maci and K'uei-hsü [qq. v.], that their opinion prevailed over that of many other officials. The Emperor was displeased with the recommendation and ignored it on the ground that Yin-ssŭ's mother was descended from a family of low degree. But when Yin-jêng, the heir-presumptive, was released from confinement, Yin-ssŭ was restored to his rank of prince of the third degree. Those who had previously recommended Yin-ssŭ were not molested, except Maci who was suspected by the Emperor of being the prime mover.
Early in 1709 Yin-jêng was reinstated as Heir Apparent, only to be degraded again in 1712. Yin-ssă, probably finding his claims of no avail, transferred his support to a younger brother, Yin-t'i [禵 q. v.]; never ceasing, however, to press his own claims as opportunity offered. One of the scholars accused of undue friendliness with Yin-ssŭ was Ho Ch'o [q. v.] whose daughter seems to have been adopted into the prince's household. For having permitted his relations with the prince to go so far, Ho was for a time imprisoned in 1715. Meanwhile Yin-t'i was appointed commander-in-chief of the armies in the northwest and was regarded by many as the Emperor's real choice for the throne.
Emperor Shêng-tsu died late in 1722. Yin-t'i was then absent from Peking, and it was Yin-chên [q. v.] who ascended the throne. As the latter was supported by Lungkodo [q. v.], commander of the gendarmerie in Peking, the adherents of Yin-ssŭ had no way to assert their claims. The new Emperor was sagacious enough to make Yin-ssů a prince of the first degree with the designation Lien (廉親王). He also appointed him Supervisor of State Affairs and president of the Board of Colonial Affairs. Yin-ssŭ was aware that these distinctions were heaped upon him to allay popular suspicion and that there could be no hope of a lasting reconciliation between himself and the Emperor. He is said to have appeared stunned when his brother ascended the throne and to have been dazed and deep in thought when the Emperor ordered him to take charge of the funeral of their father. His wife, when congratulated on the prince's new honors, is said to have remarked that she was more concerned over when they would both be beheaded. The Emperor was angered by the attitude of the prince and the princess, but refrained from action until his power was consolidated and the opposition was weakened. For more than three years Yin-ssŭ was frequently reprimanded and humiliated, and his supporters, Yin-t'ang, Sunu [qq. v.], and others, were either arrested or banished.
Early in 1726 Yin-ssŭ was interrogated about his relations with his brother, Yin-t'ang. When he swore, by the lives of the imperial family, that he had not corresponded with Yin-t'ang, he was nevertheless cut off from the imperial clan' because the Emperor, who believed him guilty, did not wish the curse to fall on the entire family. This, of course, was only a pretext for tormenting Yin-ssŭ, who before long was placed in confinement on various charges and forced to alter his personal name to Acina ('cur' in Manchu). On July 2, 1726 he was accused by courtiers of forty "crimes", including neglect of duty, formation of a coalition, planning assassinations, heaping blame on the Emperor, etc. His chief supporter, Yin-t'ang, was condemned on twenty-eight counts and imprisoned in Paoting. The Emperor evidently approved of the accusations, but was unwilling to incur the blame of publicly sentencing his brothers. He gained his ends, however, by keeping them in confinement. Yin-ssŭ died on September 30 in the prison of the Court of the Imperial Clan, and Yin-t'ang, eight days earlier at Paoting (see under Li Fu). The cause of Yin-ssŭ's death was given officially as "vomiting". The Emperor merely issued a statement that both had been "called to justice by the nether world".
It is recorded that during his confinement Yin-ssŭ declared at every meal that he did not expect to die a natural death. Courtiers suggested that his body should be dismembered, but the Emperor declined to order it so. In 1778 Emperor Kao-tsung decreed that Yin-ssŭ and Yin-t'ang be posthumously restored to the imperial clan and that the same rights be accorded their descendants. He asserted that although these two uncles had coveted the throne, there was no proof that they had engaged in treasonous activities. He admitted that his father (Emperor Shih-tsung) had in his later days expressed regret at the severity of the treatment they had received.
[1/226/7b; Ch'ing Huang-shih ssŭ-p'u (see under Fu-lung-an) 3/13b; Tung-hua lu, K'ang-hsi 47:9, 10, Yung-chêng 4:1–9; Yün-ssŭ Yün-t'ang an (The Case of Yin-ssŭ and Yin-t'ang) in Wên-hsien ts'ung-pien (see bibl. under Dorgon) no. 3, pp. 26–34.]