Yeonsan-gun (1476–1506, r. 1494–1506), born Yi Yung, was the 10th king of Korea's Joseon Dynasty. He was the eldest son of Seongjong by his second wife, Lady Yoon. He is often considered the worst tyrant in Joseon Dynasty, notorious for launching two bloody purges of the seonbi elite. He also seized a thousand women from the provinces to serve as palace entertainers, and appropriated the Seonggyungwan hall of study as a personal pleasure ground. Because of his overthrown, Yeonsan-gun did not receive a temple name.
Execution of his mother
Deposed Queen Yoon, formally known as Queen Jeheon, served Prince Yeonsan's father, Seongjong, as a concubine until the death of Queen Gonghye, Seongjong's first wife. With no royal heir, the king was urged by counselors to take a second wife to secure the royal succession. Lady Yoon was chosen for her beauty and was formally married in 1476. Several months later, she gave birth to her first son, Yi-Yung, later to become Prince Yeonsan. The new queen proved to be temperamental and highly jealous of Seongjong's concubines living inside the palace, even stooping to poisoning one in 1477. In 1479, she physically struck the king one night, leaving scratch marks. Despite efforts to conceal the injury, Seongjong's mother, Grand Queen Insu, discovered the truth and ordered Lady Yoon, now known as the Deposed Queen Yoon, into exile. After several popular attempts to restore the deposed Queen to her position at court, government officials petitioned that she be poisoned - and she was.
The Crown Prince grew up and succeeded Seongjong in 1494. During his early reign, he was a wise and able administrator who strengthened the national defense and aided poor people. He also showed signs of the violent side when he killed Jo Sa-so, one of his tutors, soon after becoming the king. He eventually learned what happened to his biological mother and tried to restore his mother's title and position posthumously. When the government officials belonging to the political faction called Sarim opposed his efforts on the account of Seongjong's will, he was displeased and looked for ways to eliminate them. In 1498 Kim Il Son, a disciple of Kim Jong-jig, included a paragraph in the royal record that was critical of King Sejo's usurpation of the throne in 1455. Kim Il Son and other followers of Kim Jong-jik were accused of treason by a rival faction, which gave Yeonsangun enough cause to order the execution of many Sarim officials and mutilation of Kim Jong-jik's remains. This is called First Literati Purge of 1498(무오사화 戊午士禍).
In 1504, Im Sa-hong revealed to Yeonsangun details of his mother's death and showed blood-stained piece of clothing, which was allegedly blood vomited by her after drinking poison. On March 20, 1504, he beat to their death two of his father's concubines, for their responsibility for his mother's death. His grandmother, Grand Queen Insu died when she was pushed by Yeonsagun after one of the altercations. He executed many government officials who supported the execution of his mother, now posthumously known as Queen Jeheon, and ordered the grave of Han Myeong-hoi to be opened and the head cut off the corpse. This is known as the Second Literati Purge of 1504(갑자사화 甲子士禍).
Suppression of speech and learning
He also closed Seonggyeongwan, the royal university, and converted it to his pleasure grounds, for which young girls and horses were gathered from the whole Korean Peninsula. He bulldozered a large residential area and evicted many residents to build hunting ground. He also forced people to involuntary labor to build another pleasure ground. Many commoners mocked and insulted the king with posters written in hangul. This provoked the anger of Yeonsangun, and he banned the use of hangul.
When ministers protested his actions, he abolished the Office of Censors (whose function was to criticize inappropriate actions or policies of the king) and Hongmoongwan (library and research center that advised the king with Confucian teachings). He ordered his ministers to wear a sign that read: "Mouth is a door that brings in disaster, the tongue is a sword that cuts off a head. A body will be in peace as long as its mouth is closed and its tongue is deep within." (口是禍之門 舌是斬身刀 閉口深藏舌 安身處處牢). When the chief ennuch Kim Cheo-sun, who served three kings, entreated Yeonsangun to change his ways, the latter killed him by shooting an arrow and cutting his limbs himself and punished his relatives down to the 7th-degree relatives. When Yeonsangun asked the royal secretaries whether such punishment was appropriate, they didn't dare to say otherwise. He also exiled a minister of rites for spilling drink given poured by the king. Many people were afraid of his despotic rule and their voices were quelled, in stark contrast to the liberal era of his father.
In 1506, the 12th year of King Yeonsan-gun, a group of officials - notably Park Won-jong, Seong Hui-an, Yoo Soon-jeong and Hong Gyeong-ju - plotted against the despotic ruler. They launched their coup on 2 September 1506, deposing the king and replacing him with his half-brother, Grand Prince Jinseong. The king was demoted to prince, and sent into exile, where he died the same year. Consort Jang Nok-su was regarded as the 'femme fatale' that encouraged Yeonsangun's misrule and was beheaded. Yeonsangun's young sons were killed as well.