1580

1580 (MDLXXX) was a leap year starting on Friday in the Julian calendar.

 Events 
March 1 – Michel de Montaigne signs the preface to his most significant work, Essays. They are published later the same year.
June 11 – Juan de Garay founds Buenos Aires.
June 25 – Publication of the Book of Concord, a collection of Lutheran confessional documents.
July 12 – Publication of the Ostrog Bible, the first complete printed Bible in a Slavic language.
September 26 – Sir Francis Drake circumnavigated the globe
Portugal loses independence to Spain following the death without heirs of king Henry of Portugal. The Habsburg rule would last until 1640.
Yermak entered Siberia with a band of 1636 men. Russia begins the conquest of Siberia.
 Khorasan Wars were fought between Abbas the Great and his father king Mohammed Khodabandeh.