정철
Jeong Cheol (Hangul: 정철, Hanja: 鄭澈; 18 December 1536 – 7 February 1594) was a Korean statesman and poet. He used the pen-names Gyeham (계함) and Songgang (송강), and studied under Kim Yunjae at Hwanbyeokdang. He was expelled by the Easterners. He was from the Yeonil Jeong clan (연일 정씨, 延日 鄭氏).