Jeong Mong-ju (Korean: 정몽주, January 13, 1338 – April 26, 1392), also known by his pen name Poeun (포은), was a Korean calligrapher, diplomat, philosopher, poet, and revolutionary. He was a major figure of opposition to the transition from the Goryeo (918-1392) dynasty to the Joseon dynasty (1392-1897). He was the last great figure of Goryeo in the late Goryeo period, and was exceptional in all aspects of academics, diplomacy, economics, military, and politics. He tried to reform Goryeo while maintaining the declining kingdom. He was opposed to Yi Seong-gye (the 1st king of Joseon) who was a radical revolutionary. He was assassinated by the men of Yi Bang-won (the 3rd king of Joseon), the son of Yi Seong-gye. Source: Wikipedia (en)