1582 (MDLXXXII) was a common year starting on Monday (link will display the full calendar) in the Julian calendar, and a common year starting on Friday (link will display full calendar) of the Proleptic Gregorian calendar. This year saw the beginning of the Gregorian calendar switch, when the papal bull Inter gravissimas introduced the Gregorian calendar, adopted by Spain, Portugal, the Polish–Lithuanian Commonwealth and most of present-day Italy from the start. In these countries, the year continued as normal through Thursday, October 4; the next day became Friday, October 15, like a common year starting on Friday. France followed two months later, letting Sunday, December 9 be followed by Monday, December 20. Other countries continued using the Julian calendar, switching calendars in later years, and the complete conversion to the Gregorian calendar was not entirely done until 1923. Events January–June January 15 – Russia cedes its conquered areas in Livonia (Northern Latvia and Southern Estonia), to the Polish–Lithuanian Commonwealth. February 10 – François, Duke of Anjou, arrives in the Netherlands, where he is personally welcomed by William the Silent. February 24 – Pope Gregory XIII proclaims the Gregorian Calendar, to come into effect later in the year. March 9 – Scryer Edward Kelley arrives at John Dee's house in London. They practice angelic magic together and Dee develops the Enochian language. April 2 – 1582 Ancuancu earthquake: Ancuancu (in modern-day La Paz Department, Bolivia) is struck by an earthquake that reportedly buries all of the inhabitants, except for one chief, who reportedly loses the ability to speak. On the place where the village had stood, the Jacha Kalla (Achocalla) valley is formed as a result of the earthquake. April 3 – Battle of Temmokuzan: Unable to reverse the collapse of Takeda clan, Takeda Katsuyori and his household commit suicide. April 14 – King James VI of Scotland signs a charter creating the Tounis College, which becomes the University of Edinburgh. April 16 – Spanish conquistador Hernando de Lerma founds the settlement of Salta, Argentina. April – Hashiba Hideyoshi begins the Siege of Takamatsu Castle. May–August – Robert Browne and his Brownist congregationalist companions are obliged to leave England, and go to Middelburg in the Netherlands. June 21 – The Incident at Honnō-ji occurs in Kyoto, Japan. July–December July 2 – Battle of Yamazaki: Counterattacking forces led by Toyotomi Hideyoshi decisively defeat Akechi Mitsuhide's smaller army; Akechi is killed while retreating