General Hong Yun-seong (Korean: 홍윤성; Hanja: 洪允成; 1425–7 October 1475) was a KoreanJoseon Dynasty politician and soldier.[1] He was a member of the court of King Sejo,[2] First and Second Vice Prime minister (also called Left and Right State Councillor, respectively) from 1467 to 1469, and Prime Minister (also called Chief State Councillor) from August 1469 to April 1470 .