On this day:

1970: The Nuclear Non-Proliferation Treaty enters into force Nuclear powers China, Russia, U.S., U.K., and France initiated the treaty in 1968. It has since been ratified by 190 nations around the world.

1616: Nicolaus Copernicus’ revolutionary book De revolutionibus orbium coelestium is banned by the Catholic Church. In the book, Copernicus claimed that the Earth revolves around the sun.

Born on this day:

1898: Zhou Enlai: Chinese politician, 1st Premier of the People’s Republic of China

1871: Rosa Luxemburg: Russian economist, philosopher

Gone on this day:

2013: Hugo Chávez: Venezuelan military officer, politician, President of Venezuela

1953: Joseph Stalin: Soviet marshal, politician, 4th Premier of the Soviet Union