Queen Jeonghui (Korean: 정희왕후; Hanja: 貞熹王后; 25 December 1418 – 15 May 1483), of the Papyeong Yun clan, was the wife of King Sejo, the seventh monarch of Joseon, and the mother of Crown Prince Uigyeong and King Yejong. She was queen of Joseon from 1455 until her husband's death in 1468. She was then styled as Queen Dowager Jaseong during the reign of her son, King Yejong, and as Grand Queen Dowager Jaseong during the reign of her grandson, King Seongjong.
Queen Jeonghui was the first Joseon royal consort to receive the title of grand queen dowager and to serve as regent. She initially took over governing during the brief reign of her sickly second son, and subsequently continued to fulfill the role following the accession to the throne of her young grandson.
The future Queen Jeonghui was born during the reign of King Sejong, as the youngest daughter and ninth child among three sons and seven daughters. Her father was Yun Beon and her mother was a lady from the Incheon Yi clan.
Lady Yun's eldest sister married the maternal uncle of her daughter-in-law, Queen Insu.
Her elder brother, Yun Sa-yun, eventually became the great-grandfather of Queen Janggyeong and Yun Im.
Her younger brother, Yun Sa-heun, eventually became the great-great-grandfather of Queen Munjeong, Yun Won-hyeong, and Yun Won-ryang (윤원량; father of King Injong's consort, Concubine Suk).
Lady Yun was a first cousin once removed of two of King Munjong's consorts, Concubine Suk and Soyong Yun (소용 윤씨), as well as Yun U (윤우) and Yun Am (윤암), the husbands of Princess Suknyong (숙녕옹주) and Princess Sukkyong (숙경옹주), King Taejong's 10th and 16th daughters, respectively.
Another first cousin once removed, Yun Gon (윤곤), married Han Myeong-hoe's aunt; they were the great-grandparents of Queen Jeonghyeon.
Her paternal grandmother was a niece of Empress Gwon (권황후), the wife of Biligtü Khan.
Her maternal grandmother was a niece of Consort Geun, making Lady Yun a first cousin twice times removed of King Chang of Goryeo.
Through her great-great-great-grandfather, she was a first cousin three times removed of Consort Hui and a second cousin twice removed of her son, King Chungjeong of Goryeo.
In 1428, shortly before her tenth birthday, Lady Yun married 11-year-old Grand Prince Suyang (then known as Grand Prince Jinpyeong), the second son of King Sejong and Queen Soheon. According to the unofficial history Songwa Japseol (송와잡설) compiled by Yi Gi (이기; 1522–1600), it was one of Lady Yun's elder sisters who was originally chosen as royal bride.
Lady Yun was greatly favored by her parents-in-law, and in 1438, she was allowed to give birth in the palace to her first son, Yi Jang. In 1441, a daughter was born, followed by a second son, Yi Hwang, in 1450. However, upon Queen Soheon's death, records note that Suyang had "one son and two daughters", so it is presumed that Lady Yun had given birth to another daughter before 1446.
Her father-in-law, King Sejong, died in 1450, and her brother-in-law, King Munjong, followed two years later. Consequently, Suyang's nephew, the 11-year-old King Danjong, acceded to the throne in 1452.
In 1453, Suyang launched a coup d'état that came to be known as the Gyeyu Purge (계유정난). It is said that when information regarding the coup leaked, Grand Prince Suyang hesitated to continue; it was Lady Yun who personally helped him put on his armor and encouraged him to proceed with his plans. He then eliminated Hwangbo In and Kim Jong-seo, and installed himself as chief state councilor.
In 1455, Suyang forced the young and weak King Danjong to abdicate, and acceded to the throne himself (posthumously King Sejo). Lady Yun thus became queen. This power shift paved the way for the Papyeong Yun clan's future uncontested influence.
Lady Yun was regarded as intelligent, with knowledge of affairs within and outside the palace. During her tenure, order returned to the Internal Court for the first time since the death of Queen Soheon a decade earlier.
Tragically, only two years after Sejo's accession, their elder son, Yi Jang (posthumously Crown Prince Uigyeong), suddenly perished. Lady Yun then orchestrated a number of schemes in order to convince Sejo to choose their younger son, 8-year-old Yi Hwang, as his successor.