June 6 - Charles X succeeds his cousin Christina on the Swedish throne. After her abdication on the same day, Christina, now the former reigning queen of a Protestant nation, secretly converts to Catholicism.
November 23 - French mathematician, scientist, and religious philosopher Blaise Pascal experiences an intense mystical vision that marks him for life.
Undated
September 7 - Twenty-three Jewish refugees from Brazil settle in New Amsterdam, forming the nucleus of what would be the largest urban Jewish community in history, the Jewish community of New York City.
The Treaty of Pereyaslav is concluded in the city of Pereyaslav during the meeting between the Cossacks of the Zaporizhian Host and Tsar Alexey I of Muscovy, following the Khmelnytsky rebellion.