The Councilors were entrusted to deliberate over key problems of state, advising the king, and conveying royal decisions to the Six Ministries.
[3][2] The council was formed under the reign of Jeongjong, just before Taejong seized power in 1400.
[4] It replaced an earlier institution called the "Privy Council," which had been dominated by Jeong Dojeon and other key figures behind the dynasty's founding.
The State Council gradually declined in importance over the 500 years of Joseon's rule.
Finally, the council was replaced by the cabinet in 1907, forced by Japanese intervention[5] Today, there's a city which was named after this organ (Uijeongbu) in Gyeonggi-do.