Chun Doo-hwan (전두환?, 全 斗 煥?, Jeon DuhwanRR, Chǒn TuhwanMR) (Hapcheon-gun, March 6, 1931-Seoul, November 23, 2021)  was a South Korean military and politician who was president of South Korea from 1980 to 1988.  
An outstanding military career, his time in politics has been controversial.  After Park Chung-hee was assassinated in 1979, he led a coup in the Armed Forces to influence the new government, and the In 1980 he ordered the dissolution of the National Assembly through another coup d'état, to then run for the presidential elections as the only candidate.  His mandate was marked by a greater rapprochement with the United States, the development of the national economy, and a series of of authoritarian policies that would end up causing his downfall in 1987, when he had to face social mobilizations in favor of democratic measures and the restoration of civil liberties.  The constitutional reform of October 1987 marked the beginning of the Sixth Republic of Korea from the south.
He was convicted in 1997 for his involvement in the 1979 coup, for the violent repression of the Gwangju uprising, and for political corruption. 
He was born on January 18, 1931 in Hapcheon (South Gyeongsang), into a large family of humble origins that was dedicated to agriculture. When he was 5 years old they moved to Daegu, where he attended basic education and lived most of his youth, with the exception of two years of residence in Jilin (China) in the last years of World War II.
After completing secondary education in 1951, Chun entered the Korean Military Academy and in 1955 graduated with the title of second lieutenant for the eleventh class. He then went through various American military schools, where he specialized in guerrilla and psychological warfare techniques, and married Rhee Soon-ja, the daughter of his superior commander at the Military Academy.
When he was captain, he supported the coup d'état of May 16, 1961 by which General Park Chung-hee came to power, and assumed the Secretary of the Interior within the military junta that ruled until 1963.  During his Ascent in the military establishment, he held positions such as personnel management in the new Korean Central Intelligence Agency (KCIA) and various regimental and divisional commands in armed conflicts, including the Vietnam War.  Shortly after returning to Korea. in 1971, he continued to progress until becoming deputy director of the Security Service (1976), the rank of general (1978), the command of the First Infantry Division (1978) and the leadership of the Security Command. 
Coup d'etat of 1980
While gaining influence within the military hierarchy, Doo-hwan formed a power chamber with officers and friends from the Military Academy, known as Hanahoe (하나회).  After Park Chung-hee was assassinated in a The attack on October 26, 1979 by the head of the KCIA, Kim Jae-gyu, opened a scene where the acting president, Choi Kyu-hah, promised democratic reforms in the Fourth Republic.  However, the military establishment had initiated an internal confrontation to seize power. Chun accused the KCIA and the Chief of the Army General Staff, Jeong Seung-hwa, of being behind the assassination.
On December 12, 1979, several soldiers linked to the Hanahoe staged a coup to take control of the Armed Forces. Chun Doo-hwan was leading the operation without the consent of the president, and other leaders such as General Roh Tae-woo were also involved in it. The next morning, the Ministry of Defense and the army barracks had been occupied, Jeong Seung-hwa had been arrested and relegated from his c