1590

January–March

• January 6 - García Hurtado de Mendoza becomes the new Viceroy of Peru. He will serve until 1596.
• January 10 - Construction of the Fortezza Nuova around the city of Livorno begins in Italy in the Grand Duchy of Tuscany on the orders of Ferdinando I de' Medici, Grand Duke of Tuscany and continues for more than 14 years.
• January 25 - Luis de Velasco y Castilla, Marquess of Salinas, becomes the new Viceroy of New Spain, a colony comprising most of Central America, Mexico and what is now a large part of the southwestern United States. Velasco will govern until 1595, and then again from 1607 to 1611.
• February 3 - Peter Ernst I von Mansfeld-Vorderort, the German-born commander of the Spanish Imperial Army captures the German fortress of Rheinberg after a four-year long siege during the Eighty Years' War.
• March 4 - Maurice of Nassau, Prince of Orange, takes Breda, by concealing 68 of his best men in a peat-boat, to get through the impregnable defenses.
• March 14 - Battle of Ivry: Henry IV of France again defeats the forces of the Catholic League, under Charles, Duke of Mayenne.
• March 21 - The Treaty of Constantinople is signed between the Ottoman Empire and the Safavid Empire, ending a 12-year war between the two nations.

  April–June

• April 4 - The Cortes of Castile approves a new subsidy, the millones.
• April 24 - Ten armed English merchant vessels of the Levant Company are intercepted by 12 galleys of the Spanish Navy while attempting to pass through the Straits of Gibraltar after trading in the Mediterranean Sea. Levant Company's Benedict Barnham, on the flagship Salomon, leads the corporate fleet in a six-hour battle and heavily damages the Spanish ships, clearing the way for the company ships to return home.
• May 7 - King Henry of Navarre, claimant to the throne of France, begins an unsuccessful attempt to besiege Paris, at the time controlled by the Catholic League. By August 30, Henry is forced to raise the siege, when Alexander Farnese, Duke of Parma comes to its rescue with a Spanish army.
• May 17 - Anne of Denmark is crowned queen consort of Scotland, at Holyrood Abbey in Edinburgh.
• June 23 - The Japanese samurai Toyotomi Hideyoshi sends an army of 15,000 men, led by generals Maeda Toshiie and Uesugi Kagekatsu, in an attack on the Hachiōji Castle in what is now Tokyo. The castle is lightly defended, by only 1,300 men, because the samurai Hōjō Ujiteru has most of his troops engaged in defending Hideyohsi's siege of Odawara. The castle is captured after one day, and later destroyed on orders of the shogun Tokugawa Ieyasu.

  July–September

• July 1 - Naresuan Maharat becomes the new ruler of Thailand as Sanphet II of the Ayutthaya Kingdom, upon the death of his father, Sanphet I.
• July 19 - The day after his 12th birthday, Ferdinand of Habsburg becomes the new Archduke of Inner Austria upon the death, in Graz, of his father Charles II. A regency council rules in the place of Ferdinand until 1596.
• July 21 - Japan's first diplomatic representatives to Europe, Itō Mancio, Michele Chijiwa, Giuliano Nakaura and Martino Hara, return to Japan after eight years, having departed on February 20, 1582.
• August 4 - In Japan, the siege of Odawara, part of Toyotomi Hideyoshi's campaign to eliminate the clan of samurais led by Hōjō Ujinao, ends with the surrender of Odawara, part of Toyotomi's unification of the country.
• August 18 - John White, governor of the Colony of Roanoke, returns to Roanoke after having left the North American colony in 1587 to get supplies. Upon arrival at, the crew of the ships Hopewell and Moonlight find that the Roanoke Colony is deserted, with the only clues to where the colonist went being the word "CRO" carved into a tree, and the word CROATOAN.
• August 27 - Pope Sixtus V dies after serving for five years, and a new papal conclave is organized, to start on September 7 at the Apostolic Palace in Rome.
• September 5 - Alexander Farnese's army forces Henry IV of France to lift the siege of Paris.
• September 15
• *After the eight day conclave, Giovanni Battista Castagna, the Cardinal-Priest of San Marcello al Corso receives the necessary two-thirds majority despite support for Cardinal Marco Antonio Colonna. Castagna becomes Pope Urban VII but contracts malaria and dies 12 days later.
• *The estimated 6.0 magnitude Neulengbach earthquake causes significant damage and some loss of life, in Lower Austria and Vienna; the effects are felt as far as Bohemia and Silesia.

  October–December

• October 6 - Two days before the scheduled papal conclave begins, Enrique de Guzmán, 2nd Count of Olivares, Spain's ambassador to the Papal States, presents the cardinals with the recommendations of King Philip II of Spain, a set of candidates whom the Spanish cardinals will support, and 30 whom they are instructed not to vote for.
• October 8 - The second papal conclave in less than four weeks opens at the Apostolic Palace in Rome, 23 days after the previous conclave had been concluded, and 53 cardinals arrive.
• October 13
• * - In what is now Myanmar, King Nanda Bayin of Burma sends a 10,000-man army, led by the Viceroy Thado Dhamma Yaza III of Prome, and General Natshinnaung to suppress a rebellion in the Shan state of Mogaung.
• *German astronomer Michael Maestlin becomes the first person to record an observation of the occultation of the planet Mars by the planet Venus.
• October 16 - Saadian invasion of the Songhai Empire: An army of 20,000 troops, led by Judar Pasha is dispatched from Marrakesh in the Saadi Sultanate, on orders of Sultan Ahmad al-Mansur. The Saadi Army's objective is to conquer the Songhai Empire, led by the Emperor Askia Ishaq II, in North Africa, corresponding to what is now the Republic of Mali.
• October 24 - After an unsuccessful search of the "lost colony" of Roanoke, English officer John White and the surviving crew of the ships Hopewell and Moonlight return to England on October 24.
• November 22 - Burmese King Nanda Bayin sends a his son, the Crown Prince Mingyi Swa and 20,000 troops to what is now Thailand.
• November 29 - A truce is signed between representatives of the Holy Roman Empire and the Ottoman Empire (ruled by Sultan Murad III.
• December 5 - Niccolò Sfondrato, Cardinal-priest of Santa Cecilia in Trastevere, is elected as the new pope and takes the name Pope Gregory XIV. Sfondrato is selected as a compromise candidate after Gabriele Paleotti falls 3 votes short of being elected.
• December 7 - North Berwick witch trials: Agnes Sampson is questioned by King James VI of Scotland, and confesses to practising witchcraft. She will be executed on January 28.

  Date unknown

• Orthodox Patriarch Meletius I of Alexandria succeeds Silvester.
• The Spanish are pushed out of southern Gelderland by the Dutch forces.

  Births

January–June

• January 9 - Simon Vouet, French painter
• January 13 - Arthur Bell, English Franciscan martyr
• January 20
• * Edward Convers, American settler
• * Benedetta Carlini, Italian mystic
• January 27 - Charles Caesar, English politician and judge
• January 30 - Lady Anne Clifford, 14th Baroness de Clifford
• February 7 - Barthold Nihus, Roman Catholic priest
• March - Roger Ludlow, one of the founders of the colony of Connecticut
• March 6 - Margaret of the Blessed Sacrament, French Discalced Carmelite nun
• March 10 - Dietrich Reinkingk, German lawyer and politician
• March 18 - Manuel de Faria e Sousa, Spanish and Portuguese historian and poet
• March 29 - Michael Reyniersz Pauw, Dutch businessman
• April 7
• * Louis de Dieu, Dutch theologian
• * John Upton, English politician
• April 18 - Ahmed I, Ottoman Sultan
• May - William Cecil, 17th Baron de Ros
• May 3 - Franco Burgersdijk, Dutch logician
• May 5
• * John Albert II, Duke of Mecklenburg
• * Jakub Sobieski, Polish noble
• May 12 - Cosimo II de' Medici, Grand Duke of Tuscany
• May 31 - Frances Carr, Countess of Somerset
• June 1 - Isaac Manasses de Pas, Marquis de Feuquieres, French soldier
• June 9 - Caspar Sibelius, Dutch Protestant minister
• June 19 - Philip Bell, British colonial governor
• June 24 - Samuel Ampzing, Dutch linguist and historian
• June 29 - Edward Rodney, English politician

  July–December

• July 3 - Lucrezia Orsina Vizzana, Italian singer and composer
• July 13 - Pope Clement X
• July 26 - Johannes Crellius, Polish-German theologian
• August 6 - Count John Louis of Nassau-Hadamar
• August 7 - Charles of Austria, Bishop of Wroclaw
• August 9 - John Webster, colonial settler and governor of Connecticut
• August 19 - Henry Rich, 1st Earl of Holland, English soldier
• August 27 - Ferruccio Baffa Trasci, Italian bishop
• August 30 - Anthony Stapley, English politician
• September 12 - María de Zayas, Spanish writer
• September 15 - Erasmus Earle, English barrister and politician
• October 3 - Anna of Pomerania, Duchess-Consort of Croy and Havré
• October 11 - William Pynchon, English colonist and fur trader in North America
• November 25 - Juan Alonso de Cuevas y Davalos, Roman Catholic prelate, Archbishop of Mexico and Antequera
• December 3 - Daniel Seghers, Flemish Jesuit brother and painter
• December 14 - John West, colonial governor of Virginia
• December 18 - William Louis, Count of Nassau-Saarbrücken