Left State Councillor counted among the four great prose masters of mid-Joseon and a central figure in diplomacy with Ming (pen name Wolsa; posthumous title Munchung)

| Life | 1564 ~ 1635 |
| Era | 조선 중기 |
| Clan | 연안 이씨 |
Yi Jeong-gwi (1564-1635) was a mid-Joseon civil official of the Yeonan clan, with courtesy name Seongjing, pen name Wolsa and posthumous title Munchung. Wikipedia calls him a fifth-generation descendant of Yi Seok-hyeong, though this site's account of the Sobugam Pansa-gong branch says great-great-grandson, so the count differs. His father was Yi Gye, his mother a daughter of Kim Pyo of Gwangju, and his wife a daughter of Gwon Geuk-ji. He became a licentiate in 1585, passed the civil examination in 1590, and accompanied King Seonjo's flight in the Imjin War.
He is best known for the 1598 Jeong Eung-tae affair: when the Ming official Jeong Eung-tae slandered Joseon, Yi went as deputy envoy and, with Yi Hang-bok, wrote a rebuttal memorial that led to Jeong's dismissal. He lectured on the classics at Ming's request and often hosted Chinese envoys, becoming a central figure in diplomacy with Ming. Under Gwanghae he went twice more on missions, and he refused to join the court petition to depose the queen dowager, which drew attacks from the Greater Northerners.
He held ministerial posts under Seonjo and Gwanghae, serving as chief academician, and under Injo rose from Right to Left State Councillor, escorting the king during Yi Gwal's rebellion and the 1627 invasion while opposing peace. He is ranked with Sin Heum, Jang Yu and Yi Sik as one of the four great prose masters of the period, and with his son Yi Myeong-han and grandson Yi Il-sang formed the first three-generation family of chief academicians. His works include the Wolsajip.
When the Ming official Jeong Eung-tae slandered Joseon in 1598, Yi Jeong-gwi went as deputy envoy and wrote the rebuttal memorial with Yi Hang-bok. It led to Jeong's dismissal and made Yi's name.
He refused to the end to join the court petition to depose the queen dowager under Gwanghae and was attacked by the Greater Northerners. Under Injo he rose to Left State Councillor and escorted the king in the Yi Gwal rebellion and the 1627 invasion.
His son Yi Myeong-han and grandson Yi Il-sang both served as chief academicians, making this the first three-generation family of its kind. He is introduced as a descendant of Yi Seok-hyeong.
His tomb and the three-generation spirit-way steles stand at Taebong-ri, Sang-myeon, Gapyeong, designated Gyeonggi Monument No. 79 in 1984.
His son Yi Myeong-han and grandson Yi Il-sang served as chief academicians; grandsons Yi Ga-sang, Yi Man-sang and Yi Dan-sang are recorded, and his maternal grandson Hong Ju-won married Princess Jeongmyeong.