768: Charlemagne and his brother Carloman I are both crowned King of the Franks

1000: Leif Ericson reaches “Vinland” (possibly L’Anse aux Meadows, Canada), reputedly becoming the first European to reach North America

1446: Korean Hangul alphabet is first published by King Sejong the Great

1831: Ioannis Kapodistrias, the first Head of State of modern Greece, is assassinated in Nafplion
‘Calutron Girls’ monitoring a mass spectrometer during the Manhattan Project. Gladys Owens, in the foreground, did not know what she was involved with until seeing this picture on a tour fifty years later.Manhattan Project

1941: US President Franklin D. Roosevelt approves an atomic program that would become the Manhattan Project

2006: North Korea conducts its first nuclear test with an estimated yield of between 0.4 and 2 kilotons

Source: Onthisday.com