The events happened on 20th December are :


1999 : Macau made an administrative region of China : On this day in 1999, 12 years after an agreement was reached between China and Portugal, several centuries of Portuguese rule ended in Macau when it became a special administrative region under Chinese sovereignty.


1989 : The United States launched Operation Just Cause, a military invasion of Panama, the initial attack focusing primarily on the Panama City headquarters of leader Manuel Noriega.


1974 : Ethiopia was declared a socialist state under the leadership of Mengistu Haile Mariam.


1971 : Pakistani President Agha Mohammad Yahya Khan transferred power to Zulfikar Ali Bhutto.


1960 : The Vietnamese National Liberation Front was formed, with the purpose of effecting the reunification of North and South Vietnam.


1860 : Following Abraham Lincoln's election as U.S. president, South Carolina became the first U.S. state to secede from the Union.


1841 : French educator Ferdinand-Édouard Buisson, who was awarded the Nobel Prize for Peace in 1927 (jointly with the German pacifist Ludwig Quidde), was born.


19th December | 21st December