1582

January–March

• January 2 – University of Würzburg is refounded.^[1]
• 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 (Julian) (March 6 Gregorian) – Pope Gregory XIII proclaims the Gregorian Calendar, to come into effect in October. Under the order, the date on the Julian calendar will be advanced by 10 days in order to synchronize the calendar date back to the equinoxes and solstices, since the gap has been increasing by one day every 100 years since the 6th century and is 10 days off schedule.^[2]
• March 9 – Scryer Edward Kelley arrives at John Dee's house in London. They practice angelic magic together and Dee develops the Enochian language.^[3]
• March – The New Testament of the Douai Bible, the translation into English by Father Gregory Martin from Latin of the New Testament, for use in the Roman Catholic Church, is published. Martin had started his work on October 16, 1578.^[4]

April–June

• 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.^[5][6] On the place where the village had stood, the Jacha Kalla (Achocalla) valley is formed as a result of the earthquake.^[7]
• 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 17 – Siege of Takamatsu: In Japan, Toyotomi Hideyoshi departs from the Himeji Castle in the modern-day Hyōgo Prefecture and begins his march westward with 20,000 soldiers to the Bitchū Province in the modern-day Okayama Prefecture. Along the way, he stops at the Kameyama Castle where he makes a rendezvous with the Ukita clan and 10,000 additional forces before proceeding toward the Takamatsu Castle.^[8]
• May 17 – The Siege of Takamatsu begins as Hideyoshi attacks the forces of Shimizu Muneharu, who has twice as many soldiers. Hideyhoshi orders an engineering project to block the Ashimori River and divert its waters to flood Takamatsu Castle.^[8]
• June 8 – Siege of Takamatsu: Heavy rains and the dikes built by Hideyoshi's forces turn the area around Takamatsu Castle into a lake.^[8]
• June 21 – (2nd day of the sixth month, Tenshō 10) The Honnō-ji Incident occurs in Kyoto in Japan, as Japanese warlord Oda Nobunaga, on the verge of unifying Japan under his rule, is assassinated following a betrayal by a rebel subject, Akechi Mitsuhide.^[9]
• June 23 – After learning of the assassination of his commander, Oda Nobunaga, Shimizu Muneharu surrenders Takamatsu Castle to Toyotomi Hideyoshi and, in return for the pledge that the castle's defenders will be spared, commits the ritual suicide of seppuku.^[10]

July–September

• July 2 – Battle of Yamazaki: Counterattacking forces led by Toyotomi Hideyoshi decisively defeat Akechi Mitsuhide's smaller army; Akechi is killed while retreating to his domain.
• July 26 – Battle of Ponta Delgada (War of the Portuguese Succession): Spanish admiral Santa Cruz decisively defeats a larger mercenary fleet from France, England, supporters of the Portuguese claimant António, Prior of Crato, and the Dutch Republic, under Filippo di Piero Strozzi (who is killed) off the Azores, the first engagement between large fleets of galleons, operating at any great distance from the mainland.^[11]

• August 23 – Raid of Ruthven in Scotland: Presbyterian nobles led by William Ruthven, 1st Earl of Gowrie kidnap King James VI of Scotland, the kingdom's 16-year-old ruler, while he is hunting in Perthshire. The Earl of Gowrie imprisons the King at Ruthven Castle as part of a coup d'etat to reform the Scottish government.^[12]
• September 28 – Ruthven and his co-conspirators arrange for John Maxwell, 8th Lord Maxwell, heir to former regent James Douglas, 4th Earl of Morton, to be installed as Scotland's regent. Douglas had been executed in 1581 for the 1567 murder of Henry Stuart, Lord Darnley, husband of Mary, Queen of Scots, and father of King James VI, who is imprisoned at Ruthven's castle.

October–December

• October 4 (Julian) (October 14 Gregorian) – The Julian calendar is discarded at the end of the day in Italy, Poland, Portugal, and Spain as Pope Gregory XIII implements the Gregorian calendar. In the nations where the calendar is accepted, Thursday, October 4 is followed the next day by Friday, October 15.^[2]
• October 26 (Julian) (November 5 Gregorian) – General Yermak Timofeyevich completes the Russian conquest of Siberia in the Battle of Chuvash Cape as Kuchum Khan abandons Qashliq, the capital of the Khanate of Sibir.^[13] The Qashliq fortress will be torn down and a new town, Tobolsk will be built 11 miles (18 km) further up the Irtysh river.
• November 29 – Ten years before he begins writing his first known plays, William Shakespeare, 18 years old, marries pregnant 26-year-old Anne Hathaway in England.^[14]
• December 9 (Julian) (December 19 Gregorian) – France discards the Julian Calendar at the end of the day and adopts the Gregorian Calendar at midnight. Sunday, December 9 is followed the next day in France by Monday, December 20.^[2]

Date unknown

• The temple complex of Kumbum is founded in Tibet.
• In Ming dynasty China:
  • Jesuit Matteo Ricci is allowed to enter the country.
  • The earliest reference is made to the publishing of private newspapers in Beijing.
• The sultanate of Morocco begins to press southward, in search of a greater share of the trans-Saharan trade.
• The Cagayan battles in the Philippines, the only recorded clashes between Spanish regular soldiers and samurai warriors.