May 1
1707 – The Act of Union, joining England and Scotland to form the Kingdom of Great Britain, takes effect.
1753 – Publication of Species Plantarum by Linnaeus, and the formal start date of plant taxonomy adopted by the International Code of Botanical Nomenclature.
1807 – The Slave Trade Act 1807 takes effect, abolishing the slave trade within the British Empire.
1820 – Execution of the Cato Street Conspirators, who plotted to kill the British Cabinet and Prime Minister Lord Liverpool.
May 2
1808 – Outbreak of the Peninsular War: The people of Madrid rise in rebellion against French occupation. Francisco de Goya later memorialized this event in his painting The Second of May 1808.
1812 – The Siege of Cuautla during the Mexican War of Independence ends with both sides claiming victory.
1829 – After anchoring nearby, Captain Charles Fremantle of HMS Challenger declares the Swan River Colony in Australia.
May 3
1715 – A total solar eclipse is visible across northern Europe and northern Asia, as predicted by Edmond Halley to within four minutes' accuracy.
1791 – The Constitution of May 3 (the first modern constitution in Europe) is proclaimed by the Sejm of–Polish-Lithuanian Commonwealth.
1802 – Washington, D.C., is incorporated as a city after Congress abolishes the Board of Commissioners, the District's founding government. The "City of Washington" is given a mayor-council form of government.
1808 – Finnish War: Sweden loses the fortress of Sveaborg to Russia.
1808 – Peninsular War: The Madrid rebels who rose on May 2 are executed near Príncipe Pío hill.
1815 – Neapolitan War: Joachim Murat, King of Naples, is defeated by the Austrians at the Battle of Tolentino, the decisive engagement of the war.
1830 – The Canterbury and Whitstable Railway is opened; it is the first steam-hauled passenger railway to issue season tickets and include a tunnel.
1837 – The University of Athens is founded in Athens, Greece.
May 4
1738 – The Imperial Theatrical School, the first ballet school in Russia, is founded.
1776 – Rhode Island becomes the first American colony to renounce allegiance to King George III.
1799 – Fourth Anglo-Mysore War: The Battle of Seringapatam: The siege of Seringapatam ends when the city is invaded and Tipu Sultan is killed by the besieging British army, under the command of General George Harris.
1814 – Emperor Napoleon arrives at Portoferraio on the island of Elba to begin his exile.
1814 – King Ferdinand VII abolishes the Spanish Constitution of 1812, returning Spain to absolutism.
May 5
1762 – Russia and Prussia sign the Treaty of St. Petersburg.
1789 – In France, the Estates-General convenes for the first time since 1614.
1809 – Mary Kies becomes the first woman awarded a U.S. patent, for a technique of weaving straw with silk and thread.
1821 – Emperor Napoleon dies in exile on the island of Saint Helena in the South Atlantic Ocean.
1821 – The first edition of The Manchester Guardian, now The Guardian, is published.
1835 – The first railway in continental Europe opens between Brussels and Mechelen.
May 6
1682 – Louis XIV of France moves his court to the Palace of Versailles.
1757 – Battle of Prague: A Prussian army fights an Austrian army in Prague during the Seven Years' War.
1757 – The end of–Konbaung-Hanthawaddy War, and the end of the Burmese Civil War (1740–1757).
1757 – English poet Christopher Smart is admitted into St Luke's Hospital for Lunatics in London, beginning his six-year confinement to mental asylums.
1782 – Construction begins on the Grand Palace, the royal residence of the King of Siam in Bangkok, at the command of King Buddha Yodfa Chulaloke.
1801 – Captain Thomas Cochrane in the 14-gun HMS Speedy captures the 32-gun Spanish frigate El Gamo.
1835 – James Gordon Bennett, Sr., publishes the first issue of the New York Herald.
1840 – The Penny Black postage stamp becomes valid for use in the United Kingdom of Great Britain and Ireland.
May 7
1697 – Stockholm's royal castle (dating back to medieval times) is destroyed by fire. It was replaced in the 18th century by the current Royal Palace.
1718 – The city of New Orleans is founded by Jean-Baptiste Le Moyne, Sieur de Bienville.
1763 – Pontiac's War begins with Pontiac's attempt to seize Fort Detroit from the British.
1765 – HMS Victory is launched at Chatham Dockyard, Kent. She was not commissioned until 1778.
1794 – French Revolution: Robespierre introduces the Cult of the Supreme Being in the National Convention as the new state religion of the French First Republic.
1798 – French Revolutionary Wars: A French force attempting to dislodge a small British garrison on the Îles Saint-Marcouf is repulsed with heavy losses.
1824 – World premiere of Ludwig van Beethoven's Ninth Symphony in Vienna, Austria. The performance is conducted by Michael Umlauf under the composer's supervision.
1832 – Greece's independence is recognized by the Treaty of London.
1840 – The Great Natchez Tornado strikes Natchez, Mississippi, killing 317 people. It is the second deadliest tornado in United States history.
May 8
1721 – In the Papal States, Cardinal Michelangelo dei Conti is elected Pope and takes the name Innocent XIII.
1788 – King Louis XVI of France attempts to impose the reforms of Étienne Charles de Loménie de Brienne by abolishing the parlements.
1794 – Branded a traitor during the Reign of Terror, French chemist Antoine Lavoisier, who was also a tax collector with the Ferme générale, was tried, convicted, and guillotined in one day in Paris.
1821 – Greek War of Independence: The Greeks defeat the Turks at the Battle of Gravia Inn.
May 9
1726 – Five men arrested during a raid on Mother Clap's molly house in London are executed at Tyburn.
1761 – Exhibition of 1761, the inaugural exhibition of the Society of Artists of Great Britain, opens at Spring Gardens in London.
May 10
1713 – Great Northern War: The Russian Navy, led by Admiral Fyodor Apraksin, landed both at Katajanokka and Hietalahti during the Battle of Helsinki.
1768 – Rioting occurs in London after John Wilkes is imprisoned for writing an article for The North Briton severely criticising King George III.
1773 – The Parliament of Great Britain passes the Tea Act, designed to save the British East India Company by reducing taxes on its tea and granting it the right to sell tea directly to North America. The legislation led to the Boston Tea Party.
1774 – Louis XVI and Marie Antoinette become King and Queen of France.
1775 – American Revolutionary War: A small Colonial militia led by Ethan Allen and Colonel Benedict Arnold captures Fort Ticonderoga.
1775 – American Revolutionary War: The Second Continental Congress takes place in Philadelphia.
1796 – War of the First Coalition: Napoleon wins a victory against Austrian forces at the Lodi Bridge over the Adda River in Italy. The Austrians lose some 2,000 men.
1801 – First Barbary War: The Barbary pirates of Tripoli declare war on the United States of America.
1824 – The National Gallery in London opens to the public.
1833 – A revolt broke out in southern Vietnam against Emperor Minh Mang, who had desecrated the deceased mandarin Le Van Duyet.
1837 – Panic of 1837: New York City banks suspend the payment of specie, triggering a national banking crisis and an economic depression whose severity was not surpassed until the Great Depression.
May 11
1713 – Great Northern War: After losing the Battle of Helsinki to the Russians, the Swedish and Finnish troops burned the entire city, so that it would not remain intact in the hands of the Russians.
1812 – Prime Minister Spencer Perceval is assassinated by John Bellingham in the lobby of the British House of Commons.
1813 – William Lawson, Gregory Blaxland, and William Wentworth discover a route across the Blue Mountains, opening up inland Australia to settlement.
May 12
1743 – Maria Theresa of Austria is crowned Queen of Bohemia after defeating her rival, Charles VII, Holy Roman Emperor.
1778 – Heinrich XI, count of the Principality of Reuss-Greiz, is elevated to Prince by Joseph II, Holy Roman Emperor.
1780 – American Revolutionary War: In the largest defeat of the Continental Army, Charleston, South Carolina, is taken by British forces.
1797 – War of the First Coalition: Napoleon Bonaparte conquers Venice.
1808 – Finnish War: Swedish-Finnish troops, led by Captain Karl Wilhelm Malmi, conquer the city of Kuopio from the Russians after the Battle of Kuopio.
1821 – The first major battle of the Greek War of Independence against the Turks is fought in Valtetsi.
May 13
1779 – War of the Bavarian Succession: Russian and French mediators at the Congress of Teschen negotiate an end to the war. In the agreement, Austria receives the part of its territory that was taken from it (the Innviertel).
1780 – The Cumberland Compact is signed by leaders of the settlers in the Cumberland River area of what would become the U.S. state of Tennessee, providing for democratic government and a formal system of justice.
1804 – Forces sent by Yusuf Karamanli of Tripoli to retake Derna from the Americans attack the city.
1830 – Ecuador gains its independence from Gran Colombia.
May 14
1747 – War of the Austrian Succession: A British fleet under Admiral George Anson defeats the French at the First Battle of Cape Finisterre.
1796 – Edward Jenner administers the first smallpox inoculation.
1800 – The 6th United States Congress recesses, and the process of moving the Federal government of the United States from Philadelphia to Washington, D.C., begins the following day.
1804 – William Clark and 42 men depart from Camp Dubois to join Meriwether Lewis at St Charles, Missouri, marking the beginning of the Lewis and Clark Expedition's historic journey up the Missouri River.
1811 – Paraguay: Pedro Juan Caballero, Fulgencio Yegros, and José Gaspar Rodríguez de Francia start actions to depose the Spanish governor.
1832 – The Battle of Stillman's Run, the first battle of the Black Hawk War, was fought.
1836 – The Treaties of Velasco are signed in Velasco, Texas.
May 15
1725 – Bach leads the first performance of his cantata Ich bin ein guter Hirt, BWV 85, about Jesus as the Good Shepherd.
1791 – French Revolution: Maximilien Robespierre proposes the Self-denying Ordinance.
1817 – Opening of the first private mental health hospital in the United States, the Asylum for the Relief of Persons Deprived of the Use of Their Reason (now Friends Hospital, Philadelphia, Pennsylvania).
1836 – Francis Baily observes "Baily's beads" during an annular eclipse.
May 16
1739 – The Battle of Vasai concludes as the Marathas defeat the Portuguese army.
1770 – The 14-year-old Marie Antoinette marries 15-year-old Louis-Auguste, Dauphin de France, who later becomes king of France.
1771 – The Battle of Alamance, a pre-American Revolutionary War battle between local militia and a group of rebels called The "Regulators", occurs in present-day Alamance County, North Carolina.
1777 – Continental Army officer Lachlan McIntosh fatally wounds Button Gwinnett, a signer of the United States Declaration of Independence, in a duel in Savannah, Georgia.
1811 – Peninsular War: The allies Spain, Portugal, and the United Kingdom fight an inconclusive battle against the French at the Albuera. It is, in proportion to the numbers involved, the bloodiest battle of the war.
1812 – Imperial Russia signs the Treaty of Bucharest, ending the Russo-Turkish War. The Ottoman Empire cedes Bessarabia to Russia.
1822 – Greek War of Independence: The Turks capture the Greek town of Souli.
1832 – Juan Godoy discovers the rich silver outcrops of Chañarcillo, sparking the Chilean silver rush.
1834 – The Battle of Asseiceira is fought; it was the final and decisive engagement of the Liberal Wars in Portugal.
May 17
1756 – The Seven Years' War formally begins when Great Britain declares war on France.
1760 – French forces besieging Quebec retreat after the Royal Navy arrives to relieve the British garrison.
1792 – The New York Stock Exchange is formed under the Buttonwood Agreement.
1805 – Muhammad Ali becomes Wali of Egypt.
1809 – Emperor Napoleon I orders the annexation of the Papal States to the French Empire.
1814 – Occupation of Monaco changes from French to Austrian.
1814 – The Constitution of Norway is signed, and Crown Prince Christian Frederick of Denmark is elected King of Norway by the Norwegian Constituent Assembly.
May 18
1695 – The 1695 Linfen earthquake in Shanxi, Qing dynasty, causes extreme damage and kills at least 52,000 people.
1756 – The Seven Years' War begins when Great Britain declares war on France.
1783 – First United Empire Loyalists reach Parrtown (later called Saint John, New Brunswick), Canada, after leaving the United States.
1794 – Battle of Tourcoing during the Flanders Campaign of the War of the First Coalition.
1803 – Napoleonic Wars: The United Kingdom revokes the Treaty of Amiens and declares war on France.
1804 – Napoleon Bonaparte is proclaimed Emperor of the French by the French Senate.
1811 – Battle of Las Piedras: The first great military triumph of the revolution of the Río de la Plata in Uruguay, led by José Artigas.
1812 – John Bellingham is found guilty and sentenced to death by hanging for the assassination of British Prime Minister Spencer Perceval.
May 19
1743 – Jean-Pierre Christin developed the centigrade temperature scale.
1749 – King George II of Great Britain grants the Ohio Company a charter of land around the forks of the Ohio River.
1776 – American Revolutionary War: A Continental Army garrison surrenders in the Battle of The Cedars.
1780 – New England's Dark Day, an unusual darkening of the day sky, was observed over the New England states and parts of Canada.
1802 – Napoleon Bonaparte founded the Legion of Honour.
1828 – U.S. President John Quincy Adams signs the Tariff of 1828 into law, sparking outrage in the South and leading to the Nullification crisis.
May 20
1714 – Johann Sebastian Bach leads the first performance of his cantata for Pentecost, Erschallet, ihr Lieder, BWV 172, at the chapel of Schloss Weimar.
1741 – The Battle of Cartagena de Indias ends in a Spanish victory, and the British begin their withdrawal towards Jamaica with substantial losses.
1775 – The Mecklenburg Declaration of Independence is allegedly signed in Charlotte, North Carolina.
1802 – By the Law of 20 May 1802, Napoleon Bonaparte reinstated slavery in the French colonies, revoking its abolition in the French Revolution.
1813 – Napoleon Bonaparte leads his French troops into the Battle of Bautzen in Saxony, Germany, against the combined armies of Russia and Prussia. The battle ended the next day with a French victory.
May 21
1703 – Daniel Defoe is imprisoned on charges of seditious libel.
1725 – The Order of St. Alexander Nevsky is instituted in Russia by Empress Catherine I. It would later be discontinued and then reinstated by the Soviet government in 1942 as the Order of Alexander Nevsky.
1758 – Ten-year-old Mary Campbell is abducted in Pennsylvania by Lenape during the French and Indian War. She returned six and a half years later.
1792 – A lava dome collapses on Mount Unzen, near the city of Shimbara on the Japanese island of Kyushu, creating a deadly tsunami that killed nearly 15,000 people.
1799 – The end of the Siege of Acre (1799): Napoleon Bonaparte abandons his siege of the Ottoman city of Acre after two months. This was the turning point of Bonaparte's Egyptian campaign and one of the first major defeats he suffered in his military career.
1809 – The first day of the Battle of Aspern-Essling between the Austrian army led by Archduke Charles and the French army led by Napoleon I of France sees the French attack across the Danube held.
May 22
1762 – Sweden and Prussia sign the Treaty of Hamburg.
1762 – Trevi Fountain is officially completed and inaugurated in Rome.
1766 – A large earthquake causes heavy damage and loss of life in Istanbul and the Marmara region.
1804 – The Lewis and Clark Expedition officially begins as the Corps of Discovery departs from St. Charles, Missouri.
1807 – A grand jury indicts former Vice President of the United States Aaron Burr on a charge of treason.
1809 – On the second and last day of the Battle of Aspern-Essling (near Vienna, Austria), Napoleon I is defeated in a major battle for the first time in his career, and repelled by an enemy army for the first time in a decade.
1816 – A mob in Littleport, Cambridgeshire, England, riots over high unemployment and rising grain costs, and the riots spread to Ely the next day.
1819 – SS Savannah leaves port at Savannah, Georgia, United States, on a voyage to become the first steamship to cross the Atlantic Ocean.
1826 – HMS Beagle departs on its first voyage.
May 23
1706 – John Churchill, 1st Duke of Marlborough, defeats a French army under Marshal François de Neufville, duc de Villeroy, at the Battle of Ramillies.
1788 – South Carolina became the eighth state to ratify the United States Constitution.
1793 – Battle of Famars during the Flanders Campaign of the War of the First Coalition.
1829 – Accordion patent granted to Cyrill Demian in Vienna, Austrian Empire.
May 24
1738 – John Wesley is converted, essentially launching the Methodist movement; the day is celebrated annually by Methodists as Aldersgate Day, and a church service is generally held on the preceding Sunday.
1798 – The Irish Rebellion of 1798, led by the United Irishmen against British rule, begins.
1813 – South American independence leader Simón Bolívar enters Mérida, leading the invasion of Venezuela, and is proclaimed El Libertador ("The Liberator").
1822 – Battle of Pichincha: Antonio José de Sucre secures the independence of the Presidency of Quito.
1832 – The First Kingdom of Greece is declared in the London Conference.
May 25
1738 – A treaty between Pennsylvania and Maryland ends the Conojocular War with the settlement of a boundary dispute and the exchange of prisoners.
1763 – First issue of Norske Intelligenz-Seddeler, the first regular Norwegian newspaper (1763–1920).
1787 – After a delay of 11 days, the United States Constitutional Convention formally convenes in Philadelphia after a quorum of seven states is secured.
1798 – United Irishmen Rebellion: Battle of Carlow begins; executions of suspected rebels at Carnew and at Dunlavin Green take place.
1809 – Chuquisaca Revolution: Patriot revolt in Chuquisaca (modern-day Sucre) against the Spanish Empire, sparking the Latin American wars of independence.
1810 – May Revolution: Citizens of Buenos Aires expel Viceroy Baltasar Hidalgo de Cisneros during the "May Week", starting the Argentine War of Independence.
1819 – The Argentine Constitution of 1819 is promulgated.
1833 – The Chilean Constitution of 1833 is promulgated.
May 26
1736 – The Battle of Ackia is fought near the present site of Tupelo, Mississippi. British and Chickasaw soldiers repel a French and Choctaw attack on the then-Chickasaw village of Ackia.
1783 – A Great Jubilee Day held at North Stratford, Connecticut, celebrates the end of fighting in the American Revolutionary War.
1805 – Napoléon Bonaparte assumes the title of King of Italy and is crowned with the Iron Crown of Lombardy in Milan Cathedral, the Gothic Cathedral in Milan.
1821 – Establishment of the Peloponnesian Senate by the Greek rebels.
1822 – At least 113 people die in the Grue Church fire, the biggest fire disaster in Norway's history.
May 27
1703 – Tsar Peter the Great founded the city of Saint Petersburg.
1798 – The Pitt–Tierney duel takes place on Putney Heath outside London. A bloodless duel between the Prime Minister of Great Britain, William Pitt the Younger, and his political opponent George Tierney.
1798 – The Battle of Oulart Hill takes place in Wexford, Ireland; Irish rebel leaders defeat and kill a detachment of militia.
1799 – War of the Second Coalition: Austrian forces defeat the French at Winterthur, Switzerland.
1813 – War of 1812: American forces capture Fort George in Canada.
May 28
1754 – French and Indian War: In the first engagement of the war, Virginia militia under the 22-year-old Lieutenant Colonel George Washington defeated a French reconnaissance party in the Battle of Jumonville Glen in what is now Fayette County in southwestern Pennsylvania.
1802 – In Guadeloupe, 400 rebellious slaves, led by Louis Delgrès, blow themselves up rather than submit to Napoleon's troops.
1830 – U.S. President Andrew Jackson signs the Indian Removal Act, which denies Native Americans their land rights and forcibly relocates them.
May 29
1733 – The right of settlers in New France to enslave natives is upheld at Quebec City.
1780 – American Revolutionary War: At the Waxhaws Massacre, the British continued attacking after the Continentals lay down their arms, killing 113 and critically wounding all but 53 that remained.
1790 – Rhode Island becomes the last of North America's original Thirteen Colonies to ratify the Constitution and become one of the United States.
1798 – United Irishmen Rebellion: Between 300 and 500 United Irishmen are executed as rebels by the British Army in County Kildare, Ireland.
1807 – Mustafa IV became Sultan of the Ottoman Empire and Caliph of Islam.
1825 – The Coronation of Charles X of France takes place in Reims Cathedral, the last ever coronation of a French monarch.
May 30
1723 – Johann Sebastian Bach assumed the office of Thomaskantor in Leipzig, presenting his first new cantata, Die Elenden sollen essen, BWV 75, in the St. Nicholas Church on the first Sunday after Trinity.
1796 – War of the First Coalition: In the Battle of Borghetto, Napoleon Bonaparte manages to cross the Mincio River against the Austrian army. This crossing forces the Austrians to abandon Lombardy and retreat to the Tyrol, leaving the fortress of Mantua as the sole remaining Austrian stronghold in Northern Italy.
1806 – Future U.S. President Andrew Jackson kills Charles Dickinson in a duel.
1814 – The First Treaty of Paris is signed, restoring the French frontiers to their 1792 extent and returning the House of Bourbon to power.
1815 – The East Indiaman Arniston is wrecked during a storm at Waenhuiskrans, near Cape Agulhas, in present-day South Africa, with the loss of 372 lives.
May 31
1775 – American Revolution: The Mecklenburg Resolves are adopted in the Province of North Carolina.
1790 – Manuel Quimper explores the Strait of Juan de Fuca.
1790 – The United States enacts its first copyright statute, the Copyright Act of 1790.
1795 – French Revolution: The Revolutionary Tribunal is suppressed.
1805 – French and Spanish forces begin the assault against British forces occupying Diamond Rock, Martinique.
1813 – In Australia, William Lawson, Gregory Blaxland, and William Wentworth reach Mount Blaxland, effectively marking the end of a route across the Blue Mountains.