What is "yeonguijeong"

Yeonguijeong was a title created in 1400, during the Joseon Dynasty of Korea (1392-1910) and given to the Chief State Councillor as the highest government position of " Uijeongbu" (State Council). Existing for over 500 years, the function was handed over in 1895 during the Gabo Reform to the newly formed position of Prime Minister of Korea. Only one official at a time was appointed to the position and though was generally called Yeongsang, was also referred to as Sangsang, Sugyu or Wonbo. Although, the title of Yeonguijeong was defined as the highest post in charge of every state affairs by law, its practical functions changed drastically depending on the particular King and whether that King's power was strong or weak.