Old Style and New Style dates

changes in calendar conventions from Julian to Gregorian dates

142 dated entries naming Old Style and New Style dates, drawn from 84 separate years between 1584 CE and 1917 CE. Nothing here is written by us: each line is the sentence a Wikipedia year article used, and the link beside it opens the exact revision.

Also written as New Style, Old Style in the source articles; Wikipedia redirects those to the same subject, so their entries are on this page.

JSON Wikipedia article Wikidata Q1922815

16th century

1584March 28 (O.S. March 18) – Ivan the Terrible, ruler of Russia since 1533, dies; he is succeeded as Tsar by his son, Feodor.source
1588August 8 (July 29 Old Style) – Battle of Gravelines: The Spanish Armada is defeated by the English naval force off the coast of Gravelines, in the Spanish Netherlands (modern France).source
1588August 19 (August 9 Old Style) – Speech to the Troops at Tilbury by Queen Elizabeth I.source
1593March 7 (February 25 Old Style) – The Uppsala Synod discontinues; the Liturgical Struggle between the Swedish Reformation and Counter-Reformation ends in Sweden.source
1595April 8 (March 29 O.S.) – Combined Taungoo–Lan Na armies break the rebel Thado Dhamma Yaza's siege of Taungoo, in modern-day Myanmar.source

17th century

1605November 5 (O.S.) – The Gunpowder Plot, a scheme to bomb England's Palace of Westminster during the opening of Parliament, is foiled after Sir Thomas Knyvet is tipped off, and finds Catholic plotter Guy Fawkes in a cellar below the Parliament building. Knyvet orders a search of the area and 36 barrels of gunpowder are found. Fawkes is arrested for trying to assassinate King James I and the members who had been scheduled to sit together in Parliament the next day.source
1620July 25 (July 15 OS) – The armed merchant ship Mayflower embarks about 65 emigrants for New England at or near her home port of Rotherhithe on the Thames east of London; about July 29 (July 19 OS) she anchors in Southampton Water.source
1620August 1 (July 22 OS) – The ship Speedwell departs Delfshaven with English separatist Puritans from Leiden bound to rendezvous with the Mayflower; on August 5 (July 26 OS) she anchors in Southampton Water.source
1620August 15 (probable date; August 5 OS) – Mayflower and Speedwell depart together from Southampton, but are forced to put back into Dartmouth, Devon, for repairs to a leak in the latter ship on August 22 or 23 (August 12 or 13 OS).source
1620September 2 (August 23 OS) – Mayflower and Speedwell depart together from Dartmouth; they are well out into the Atlantic when the Speedwell is again found to be leaking.source
1620September 16 (September 6 OS) – Mayflower departs from Plymouth in England on her third attempt to cross the Atlantic. The Pilgrims on board comprise 41 "saints" (English separatists largely from Holland), 40 "strangers" (largely secular planters from London), 23 servants and hired workers, together with c. 30 crew.source
1620November 21 (November 11 OS) – The Mayflower arrives inside the tip of Cape Cod (named from the Concord voyage of 1602), at what becomes known as Provincetown Harbor, with the Pilgrims and Planters; 41 Plymouth Colony settlers sign the Mayflower Compact, the first governing document of the colony, on board the ship.source
1626November 6 (O.S.) – The ship Arms of Amsterdam arrives in Europe from New Netherland (left September 23) with the news: "They have purchased the Island Manhattes [Manhattan] from the Indians for the value of 60 guilders."source
1630September 17 (September 7 Old Style) – The settlement of Boston, Massachusetts Bay Colony is founded.source
1632November 16 (November 6 Old Style) – Thirty Years' War: Battle of Lützen in Saxony – Swedish king Gustavus Adolphus leads an assault on Wallenstein's army, but is killed early in the battle, despite which the Swedish commanders manage to rally the army and eventually defeat Wallenstein, who withdraws from Saxony. Following the death of Gustavus Adolphus, he is succeeded as ruler of Sweden by his six-year-old daughter Christina, while five regents (headed by Axel Oxenstierna) govern the country. On November 17, Gottfried zu Pappenheim, Field Marshal of the Holy Roman Empire, dies from wounds sustained in the battle.source
1636March 5 (February 24 Old Style) – King Christian IV of Denmark and Norway gives an order, that all beggars that are able to work must be sent to Brinholmen, to build ships or to work as galley rowers.source
1636March 13 (March 3 Old Style) – A "great charter" to the University of Oxford establishes the Oxford University Press, as the second of the privileged presses in England.source
1636August 25 (August 15 Old Style) – The covenant of the Town of Dedham, Massachusetts Bay Colony is first signed.source
1636September 18 (September 8 Old Style) – A vote of the Great and General Court of the Massachusetts Bay Colony establishes New College (Harvard University), as the first college founded in the United States.source
1636October 4 (September 24 Old Style) – Thirty Years' War – Battle of Wittstock: A Swedish-allied army defeats a combined Imperial-Saxon army.source
1636December 23 (December 13 Old Style) – The Massachusetts Bay Colony organizes three militia regiments to defend the colony against the Pequot Indians. This organization is recognized today as the founding of the United States National Guard.source
16434 January (N.S.) – Isaac Newton, mathematician and physicist (died 1727)source
1644November 23 – Battle of Jüterbog (December 3 New Style): Sweden's forces defeat those of the Holy Roman Empire.source
1644December 8 (December 18 New Style) – As Christina comes of age, she is made ruling queen of Sweden.source
1645August 23 (August 13 Old Style) – The Treaty of Brömsebro is signed between Sweden and Denmark–Norway, ending the Torstenson War and ceding Jemtland, Herjedalen, Gotland and Ösel (Saaremaa) to Sweden, which also holds the province of Halland for a period of 30 years, as a guarantee.source
16532–3 June (12–13 June New Style) – First Anglo-Dutch War: Battle of the Gabbard off the coast of Suffolk: The English navy defeats the Dutch fleet, which loses 17 ships.source
165318–20 February (28 February–2 March New Style) – First Anglo–Dutch War: Battle of Portland off the Isle of Portland. Both sides claim victory but the English retain control of the Channel.source
1654June 16 (June 6 Old Style) – Charles X Gustav succeeds his cousin Christina on the Swedish throne. After her abdication on the same day, Christina, now the former reigning queen of a Protestant nation, secretly converts to Catholicism.source
1658March 8 (February 26 OS) – The peace between Sweden and Denmark-Norway is concluded in Roskilde by the Treaty of Roskilde, under which Denmark is forced to cede significant territory. This leads to Sweden reaching its territorial height during its time as a great power.source
166023 May (2 June N.S.) – Charles II embarks from Scheveningen on HMS Royal Charles, captained by Edward Montagu (created Earl of Sandwich two months later).source
16653 June (13 June N.S.) – Second Anglo-Dutch War: English naval victory at the Battle of Lowestoft.source
1665June 13 (June 3 O.S.) – Second Anglo-Dutch War – Battle of Lowestoft: The English Navy, under James Stuart, Duke of York, is victorious against the Dutch.source
16661–4 June (11–14 June New Style) – Second Anglo-Dutch War: Four Days' Battle – The Dutch Republic fleet under Michiel de Ruyter defeats the English in the North Sea in one of the longest naval engagements in history.source
166721 July (Old Style – 31 July New Style) – The Second Anglo-Dutch War is ended by the Treaty of Breda, negotiation of which began on 14 May and coming into effect in August. In the Americas, the Dutch retain control of Surinam, the English retain New Netherland and the French Acadia.source
1669January 11 – Peter Talbot is appointed Roman Catholic Archbishop of Dublin and Primate of Ireland (consecrated at Antwerp 29 April (9 May New Style)).source
1672February 25 (6 March N.S.) – John O'Molony is consecrated as Roman Catholic Bishop of Killaloe in Paris.source
167228 May (7 June New Style) – the first naval battle of the Third Anglo-Dutch War is fought at the Battle of Solebay off Southwold; indecisive.source
167328 May (7 June New Style) – Third Anglo-Dutch War: First Battle of Schooneveld – The Dutch Republic fleet commanded by Michiel de Ruyter defeats the allied Anglo-French fleet commanded by Prince Rupert of the Rhine.source
16749 February (19 February New Style) – England and the Dutch Republic sign the Treaty of Westminster ending the Third Anglo-Dutch War.source
167916 September (O.S.) / 26 September – The Peace of Lund ends the Scanian War between Denmark-Norway and the Swedish Empire.source
1680August 20 (August 10 Old Style) – The settlement of Karlskrona in Sweden is founded, as the Royal Swedish Navy relocates there.source
1688May 9 (April 29 OS) – Friedrich Wilhelm, the Great Elector of Brandenburg-Prussia, dies. Friedrich III becomes Elector of Brandenburg-Prussia until 1701, when he becomes the first King of Prussia, as Friedrich I.source
16885 November (15 November NS) – Glorious Revolution begins: William lands at Brixham; James is prevented from meeting him in battle because many of his officers and men desert to the other side.source
1688November 11 (November 1 OS) – Glorious Revolution: William III of Orange sets sail a second time from Hellevoetsluis, the Netherlands, to take over England, Scotland and Ireland from King James II of England.source
1688November 15 (November 5 OS) – The Glorious Revolution begins: William of Orange lands at Torbay, England with a multinational force of 20,000 soldiers. He makes no claim to the British Crown, saying only that he has come to save Protestantism and to maintain English liberty, and begins a march on London.source
1688November 19 (November 9 OS) – William of Orange captures Exeter, after the magistrates flee the city.source
1688November 20 (November 10 OS) – The Wincanton Skirmish between forces loyal to James II led by Patrick Sarsfield and a party of Dutch troops is one of the few armed clashes in England during the Glorious Revolution.source
1689January 22 (January 12, 1688 O.S.) – Glorious Revolution in England: The Convention Parliament is convened to determine if King James II of England, the last Roman Catholic British monarch, vacated the throne when he fled to France, at the end of 1688. The settlement of this is agreed on 8 February.source
1689February 23 (February 13, 1688 O.S.) – William III and Mary II are proclaimed co-rulers of England, Scotland and Ireland.source
16891 May (11 May N.S.) – Battle of Bantry Bay between the English Royal Navy under the Earl of Torrington and the French fleet under the Marquis de Châteaurenault. The French are able to protect their transports unloading supplies for James II and withdraw unpursued.source
16901 July (O.S.) – Battle of the Boyne in Ireland: William III defeats the deposed James II who returns to exile in France.source
16901 July (O.S.) – Battle of the Boyne: William III defeats the deposed James II of England, who returns to exile in France from Kinsale.source
1692May 18 – (O.S) Joseph Butler, English bishop and philosopher (died 1752)source
169317 June (27 June New Style) – Nine Years' War: The French fleet defeats the joint Dutch and English fleet at the Battle of Lagos off Portugal.source
1697May 17 (May 7 Old Style) – The 13th century royal Tre Kronor ("Three Crowns") castle in Stockholm burns to the ground, and a large portion of the royal library is destroyed.source
1699May 1 (O.S.) – A series of five student orations at the College of William & Mary precipitate the Colony of Virginia's capital moving from Jamestown to Middle Plantation, resulting in the establishment of Williamsburg.source
1700August 18 (August 7 O.S.) – The Peace of Travendal is concluded between the Swedish Empire, Denmark–Norway and Holstein-Gottorp in Traventhal. On the same day, Augustus II, King of Poland, and Peter the Great, Tsar of Russia, enter the war against Sweden.source
1700August 18 (August 7 OS) – Peace of Travendal concluded between the Swedish Empire, Denmark-Norway and Holstein-Gottorp in Traventhal. On the same day, Augustus II, King of Poland, and Peter the Great, Tsar of Russia, enter the war against Sweden.source
1700November 30 (November 19 O.S.; November 20 Swedish calendar) – Battle of Narva in Estonia: Having led his army of 8,000 on a forced march from Denmark to Estonia, Charles XII of Sweden routs the huge Russian army.source
1700November 30 (November 19 OS; November 20 Swedish calendar) – Battle of Narva in Estonia. Having led his army of 8,000 on a forced march from Denmark to Estonia, Charles XII of Sweden routs the huge Russian army at Narva.source

18th century

170116 September (N.S.) – on the death of the deposed King James VII of Scotland in exile at the Château de Saint-Germain-en-Laye in France, his son James Francis Edward Stuart declares himself James VIII (and III of England and Ireland).source
170116 September (N.S.) — following the death of the deposed King James II of England in exile in France, his son Prince James Francis Edward Stuart becomes the new claimant to the thrones of England as King James III and Scotland as King James VIII; Louis XIV of France, the Papal States, and Philip V of Spain recognise him as the rightful heir.source
1702March 19 (March 8 Old Style) – Princess Anne Stuart, daughter of the late King James II and younger sister of his successor, Mary II (who had reigned jointly with her husband, William III, as William and Mary until her death in 1694), ascends the English, Scottish and Irish thrones upon William's death. In her first speech to the English Parliament, made three days later, she tells the assembly "As I know my heart to be entirely English, I can very sincerely assure you there is not anything you can expect or desire from me which I shall not be ready to do for the happiness and prosperity of England." Anne is the mother of 17 children by her husband, Prince George of Denmark and Norway, but none will survive childhood, and she will die without an heir, bringing an end to the reign of the House of Stuart and enabling the Hanoverian Succession. After the death of William, the States General of the Netherlands do not appoint a new stadtholder, and so the Dutch Republic becomes a true republic again, starting the Second Stadtholderless Period.source
1702March 22 (March 11 Old Style) – The first regular English-language national newspaper, The Daily Courant, begins publication on Fleet Street in the City of London, initially by Elizabeth Mallet; it covers only foreign news.source
1702May 14 (N.S.) – War of the Spanish Succession: War is declared on France by the Grand Alliance (Kingdom of England, Dutch Republic and Holy Roman Empire).source
170326–29 November (7–10 December N.S.) – the Great Storm of 1703, an Atlantic hurricane ravages southern England and the English Channel, killing at least 8,000, chiefly at sea.source
1703May 27 (May 16 OS) – The city of Saint Petersburg, Russia is founded, following Peter the Great's reconquest of Ingria from Sweden during the Great Northern War.source
1703December 7–10 (November 26–29 O.S.) – The Great Storm of 1703, an extratropical cyclone, ravages southern England and the English Channel, killing at least 8,000, mostly at sea. The Eddystone Lighthouse off Plymouth is destroyed in the storm together with its designer Henry Winstanley and many buildings on land are damaged.source
1704August 3 (July 23 Old Style) – War of the Spanish Succession – Gibraltar is captured from Spain, by English and Dutch forces under Sir George Rooke.source
170714 April (25 April New Style) – At the Battle of Almansa (Spain) in the War of the Spanish Succession, the Bourbon army of Spain and France (with Irish mercenaries) under the French-born Englishman James FitzJames, 1st Duke of Berwick, soundly defeats the allied forces of Portugal, England, and the Dutch Republic led by the French-born Huguenot in English service Henri de Massue, Earl of Galway.source
1707April 14 (April 25 New Style) – at the Battle of Almansa (Spain) in the War of the Spanish Succession, the Bourbon army of Spain and France (with Irish mercenaries) under the French-born Englishman James FitzJames, 1st Duke of Berwick, soundly defeats the allied forces of Portugal, England, and the Dutch Republic led by the French-born Huguenot in English service Henri de Massue, Earl of Galway.source
1707April 25 (April 14 Old Style) – War of the Spanish Succession – Battle of Almansa: The Bourbon army of Spain and France (with Irish mercenaries) under the French-born Englishman James FitzJames, 1st Duke of Berwick, soundly defeats the allied forces of Portugal, England, and the Dutch Republic led by the French-born Huguenot (in English service) Henri de Massue, Earl of Galway. Following this, Philip V of Spain promulgates the first Nueva Planta decrees, bringing the Kingdoms of Valencia and Aragon under the laws of the Crown of Castile.source
1707May 12 (May 1 Old Style) – The new sovereign state of Great Britain comes into being, as a result of the Acts of Union, which combine the Kingdoms of Scotland and England into a single united Kingdom of Great Britain, and merge the Parliaments of England and Scotland, to form the Parliament of Great Britain.source
170712 May (1 May Old Style) – The new sovereign state of Great Britain comes into being as a result of the Acts of Union which ratified the Treaty of Union: the kingdoms of England and Scotland are combined into a single, United Kingdom and merge the Parliaments of England and Scotland to form the Parliament of Great Britain. The Equivalent, a sum of £398,000, is paid to Scotland by the English government due to Scotland now taking on shared responsibility for England’s national debt.source
1708September 28 (O.S.); September 29 (Swedish calendar); October 9 (N.S.) – Great Northern War: Battle of Lesnaya – Peter the Great of Russia defeats the forces of the Swedish Empire.source
1709June 27 (June 28 in the Swedish calendar; July 8 New Style) – Great Northern War: Battle of Poltava: In Ukraine, Peter the Great, Tsar of Russia, defeats Charles XII of Sweden, thus effectively ending Sweden's role as a major power in Europe.source
1709July 8 (June 27 Old Style; June 28 in the Swedish calendar) – Great Northern War: Battle of Poltava in the Cossack Hetmanate (Ukraine) – Peter the Great leads forces of the Tsardom of Russia to a decisive victory over Swedish forces under Charles XII, ending the Swedish invasion of Russia and effectively ending Sweden's role as a major power in Europe.source
170931 August (11 September NS) – War of the Spanish Succession: Battle of Malplaquet – troops of the Dutch Republic, Habsburg monarchy, Great Britain and the Kingdom of Prussia led by the Duke of Marlborough drive the French from the field but suffer twice as many casualties. The song "For He's a Jolly Good Fellow" is based on the French song "Marlbrough s'en va-t-en guerre" composed following this battle.source
1709September 11 (August 31 Old Style) – War of the Spanish Succession: Battle of Malplaquet – Troops of the Dutch Republic, Habsburg monarchy, the Kingdom of Great Britain and the Kingdom of Prussia, led by the Duke of Marlborough, drive the French from the field, but suffer twice as many casualties.source
171624 December (4 January 1717 New Style) – Britain, France and the Dutch Republic sign the Triple Alliance in an attempt to maintain the Treaty of Utrecht (1713), Britain having signed a preliminary alliance with France on 17 November (28 November New Style).source
1717January 4 (December 24, 1716 Old Style) – The kingdoms of Great Britain, France and the Dutch Republic sign the Triple Alliance, in an attempt to maintain the Treaty of Utrecht (1713), Britain having signed a preliminary alliance with France on November 28 (November 17) 1716.source
17174 January (24 December 1716 OS) – Triple Alliance treaty between France, the Dutch Republic and Great Britain against Spainsource
1718December 11 (November 30 Old Style) – King Charles XII of Sweden is killed at the Siege of Fredriksten in the Great Northern War, the last European monarch to die on a battlefield. His death ends the first era of absolute monarchy in Sweden. Five days later, when the news reaches Stockholm, his sister Princess Ulrika Eleonora proclaims herself Queen regnant of Sweden.source
1718December 11 (November 30 Old Style) – King Charles XII of Sweden (shot during siege) (born 1682)source
1719February 3 (January 23 Old Style) – The Riksdag of the Estates (the parliament of Sweden) recognizes Ulrika Eleonora's claim to the Swedish throne, after she has agreed to sign a new Swedish constitution. Thus, she is recognized as queen regnant of Sweden.source
1719March 26 Old Style (1720 New Style) – the Dependency of Ireland on Great Britain Act 1719 is passed by the Parliament of Great Britain.source
1720March 11 (February 29 Old Style) – Queen Ulrika Eleonora of Sweden resigns, to let her husband Frederick I take over as king of Sweden. She had desired a joint rule, in a similar manner to William III and Mary II in Britain, but as the Riksdag of the Estates (Sweden's parliament) refuses this, she abdicates in her husband's favour instead.source
1720March 26 – the Parliament of Great Britain passes the Dependency of Ireland on Great Britain Act 1719 [that is, 1719 Old Style, meaning 1720 in New Style dating], also known as the Declaratory Act 1720, declaring the right of the Parliament of Great Britain to legislate for Ireland and denying the appellate jurisdiction of the Irish House of Lords.source
1721September 10 (August 23 Old Style) – The Treaty of Nystad is signed, ending the Great Northern War.source
1721November 2 (October 22 Old Style) – The Romanov and architect of the Great Northern War Peter I, is proclaimed the first Emperor of All the Russias. This replaces the 174-year-long Tsardom of Russia with the Russian Empire, which will collapse almost 200 years later in 1917.source
172316 June (5 June O.S.) – Adam Smith, Scottish economist and philosopher (died 1790)source
1725February 8 – (January 28 Old Style) Catherine I becomes Empress of Russia on the death of her husband, Peter the Great.source
1726January 23 (January 12 Old Style) – The Conventicle Act (Konventikelplakatet) is adopted in Sweden, outlawing all non-Lutheran religious meetings outside of church services.source
1726November 8 (October 28 Old Style) – Jonathan Swift's satirical novel Gulliver's Travels is first published (anonymously) in London; it sells out within a week.source
1727June 22 (July 11 Old Style) – George, Prince of Wales, becomes King George II of Great Britain, on the death of his father.source
172827 October (O.S.) – James Cook, naval captain and explorer (died 1779)source
1739June 13 – (June 2 Old Style); The Royal Swedish Academy of Sciences is founded in Stockholm, Sweden.source
1743March 28 (March 17 O.S.) – Yekaterina Vorontsova-Dashkova, Russian princess, courtier and patron of the arts and sciences (died 1810)source
174316 June (27 June New Style) – War of the Austrian Succession: the Battle of Dettingen is fought in Bavaria; King George II leads the troops of Britain and Brunswick to victory over the French – the last time a reigning British monarch participates in a battle. The Prime Minister, Spencer Compton, Earl of Wilmington, is also present, observing from a carriage. George Frideric Handel writes the oratorio Dettingen Te Deum in celebration of the King's victory.source
1743June 27 (June 16 O.S.) – War of the Austrian Succession – Battle of Dettingen in Bavaria: British forces, in alliance with those of Hanover and Hesse, defeat a French army under the duc de Noailles; King George II of Great Britain (and Elector of Brunswick) leads his own troops, the last British king to do so.source
174327 June (16 June O.S.) – War of the Austrian Succession: Battle of Dettingen in Bavaria – British forces, including the Royal Scots Greys, the Scots Guards and the Royal Scots Fusiliers, in alliance with those of Hanover and Hesse, defeat the French; King George II of Great Britain (and Elector of Brunswick) leads his own troops, the last reigning British monarch to participate in a battle.source
1743August 18 (August 7 Old Style) – Russia and Sweden sign the Treaty of Åbo.source
17441 August (12 August New Style) – Battle of Velletri in the Kingdom of Naples: Spanish-Neapolitan forces defeat those of the Archduchy of Austria. Irish mercenaries fight on both sides.source
1745August 6 (July 26 Old Style) – The first recorded women's cricket match takes place in Surrey, England.source
174725 March [ O.S. 14 March] – Alexander Bezborodko, (died 1799)source
1751March 25 – For the last time, New Year's Day is legally on March 25, in England and Wales and "in all his Majesty's Dominions in Europe, Asia, Africa and America" due to the Calendar (New Style) Act 1750. The months of January 1751, February 1751 and most of March 1751 did not exist in British territories: those months were recorded as the last three of 1750 according to the Old Style dating system; the equivalent months a year later were recorded as the first three of 1752 under the New Style system.source
1751May 27 (May 13 Old Style) – Adoption of the Gregorian calendar: Royal assent is given to An Act for Regulating the Commencement of the Year; and for Correcting the Calendar now in Use (the "Calendar Act") passed by the Parliament of Great Britain, introducing the Gregorian Calendar, correcting the eleven-day difference between Old Style and New Style dates and making 1 January legally New Year's Day from 1752 in the British Empire. It is largely promoted by George Parker, 2nd Earl of Macclesfield.source
175127 May – adoption of the Gregorian calendar: royal assent is given to An Act for Regulating the Commencement of the Year; and for Correcting the Calendar now in Use (the "Calendar Act") passed by Parliament, introducing the Gregorian Calendar, correcting the eleven-day difference between Old Style and New Style dates and making 1 January legally New Year's Day from 1752 in the British Empire. It is largely promoted by George Parker, 2nd Earl of Macclesfield.source
17523–13 September inclusive – these dates are omitted from the calendar in Great Britain and Ireland as part of the adoption of the Gregorian calendar, correcting the discrepancy between Old Style and New Style dates, under terms of the Calendar (New Style) Act 1750.source
17523–13 September – these dates are omitted from the calendar in Britain as part of the adoption of the Gregorian calendar to correct the discrepancy between Old Style and New Style dates.source
1752September 2 of Julian calendar (Wednesday) (September 13 "New Style")– Great Britain and the British Empire use the Julian calendar for the last time and adopt the Gregorian calendar, making the next day Thursday, September 14 in the English-speaking world. A newspaper at the time notes the next day that "Altho' we have more than once, for the Information of our Readers, publish'd some Accounts of the Alteration of the Style, which took Place this Day, agreeable to a late Act of Parliament, in all his Majesty's Dominions in Europe, Asia, Africa and America" and notes that "The Supputation of the Year began on the first Day of January last, and for the future the first Day of that Month will be stiled the first Day of every Year in all Accounts whatsoever, which Supputation or Reckoning never took Place before this Year in any Courts of Law until the 25th Day of March", and adds, "This Day, had not this Act passed, would have been the 3rd of September, but is now reckoned the 14th, eleven nominal Days being omitted."source
1770August 1 (July 21 O.S.) – Russo-Turkish War (1768–74) – Battle of Kagul: Russian commander Pyotr Rumyantsev routs 150,000 Turks.source
1774June 20 (June 9 O.S.) – Russo-Turkish War (1768–1774): Battle of Kozludzha – The Imperial Russian Army, led by Alexander Suvorov, routs numerically superior Ottoman Empire forces.source
1780March 11 – The First League of Armed Neutrality is formed by Russia with Denmark and Sweden to try to prevent the British Royal Navy from searching neutral vessels for contraband (February 28 O.S.).source

19th century

1802July 5 (June 23 O.S.) – Pavel Nakhimov, Russian admiral (died 1855)source
1820January 27 (NS, January 15 OS) – An Imperial Russian Navy expedition, led by Fabian Gottlieb von Bellingshausen in Vostok with Mikhail Petrovich Lazarev, sights the Antarctic ice sheet.source
1825December 1 (November 19 O.S.) – Nicholas I succeeds his brother Alexander I, as emperor.source
1853November 30 (November 18 O.S.) – Crimean War: Battle of Sinop – The Russian fleet destroys the Turkish fleet.source
1855July 12 (June 30 O.S.) – Pavel Nakhimov, Russian admiral (born 1802)source
1855September 9 (August 28 O.S.) – Crimean War: Siege of Sevastopol (1854–1855) – Sevastopol falls to French and British troops.source
1857September 22 (September 10 O.S.) – Russian ship of the line Lefort sinks in the Gulf of Finland during a sudden squall with the loss of 826 lives; 30 other ships are wrecked in the same storm.source
1859January 24 (O. S.) – Under the rule of Alexandru Ioan Cuza, the provinces of Wallachia and Moldavia are united under the jurisdiction of the Ottoman Empire. It would be a principal step in forming the modern state of Romania.source
1866July 13 (July 1 Old Style) – The first Constitution of Romania is issued.source
1876May 2 (April 20 O.S.) – April Uprising of 1876 in Ottoman Bulgaria begins: members of the Bulgarian Revolutionary Central Committee rise up against their Ottoman Empire overlords. Over the course of one month and 6 days, the rebellion is suppressed by irregular Ottoman bashi-bazouk units that engage in indiscriminate slaughter of both rebels and non-combatants, killing 15,000–30,000, including the principal rebel leaders and around 5,000 in the Batak massacre. Although the rising does not immediately succeed in its aims, reports of the "Bulgarian Horrors" cause a public outcry in the West and the liberation of Bulgaria is achieved two years later.source
1877May 21 (May 9 O.S.) – By a speech in the Parliament of Romania by Mihail Kogălniceanu, the country declares itself independent from the Ottoman Empire (recognized in 1878 after the end of the Romanian independence war).source
1878March 3 (February 19 O.S.) – Treaty of San Stefano signed between the Russian and Ottoman Empires following Russian victory in the Russo-Turkish War (1877–1878) provides for establishment of an autonomous Principality of Bulgaria (although not as large as originally envisaged). Russia however regards the treaty as a preliminary one only, refusing on March 25 a British proposal to lay it before a European congress, and matters are finally settled in July's Treaty of Berlin.source
1881February 24 (February 12 Old Style) – Qing dynasty China signs the Treaty of Saint Petersburg with the Russian Empire providing for the return to China of the eastern part of the Ili Basin.source
1881March 13 (March 1 Old Style) – Assassination of Alexander II of Russia: Emperor Alexander II of Russia ("the Liberator") is killed near his palace in Saint Petersburg when bombs are thrown at him, an act committed by the revolutionary socialist group Narodnaya Volya coordinated by Sophia Perovskaya but falsely blamed upon Russian Jews. He is succeeded by his son, Alexander III. The assassin Ignacy Hryniewiecki is also killed by his own bomb.source
1881March 26 (March 14 Old Style) – The Principality of Romania is proclaimed the Kingdom of Romania.source
1881May 22 (May 10 Old Style) – Prince Karl of Hohenzollern-Sigmaringen is crowned King of Romania.source
1882March 6 (February 22 Old Style) – The Principality of Serbia becomes the Kingdom of Serbia following a proclamation.source
1893October 28 (October 16 O.S.) – In Saint Petersburg (Russia), Pyotr Ilyich Tchaikovsky conducts the first performance of his Symphony No. 6 in B minor, Pathétique, nine days before his death.source
1899November 7 – (October 26 Old Style) – Anton Chekhov's Uncle Vanya receives its Russian metropolitan première at the Moscow Art Theatre.source

20th century

1903July 30–August 23 (July 17–August 10, O.S.) – The Second Congress of the All-Russian Social Democratic Labour Party is held in exile in Brussels, transferring to London.source
1905January 22 (January 9 O.S.) – The Bloody Sunday massacre of peaceful Russian demonstrators at the Winter Palace in Saint Petersburg takes place, leading to an unsuccessful uprising.source
1905October 13 O.S: The Saint Petersburg Soviet holds its first meeting, the first elected workers' Soviet (council) in Russia.source
1908June 30 (June 17 OS) – The Tunguska event near the Podkamennaya Tunguska River in Krasnoyarsk Krai, Siberia, Russian Empire, is believed to have been caused by the air burst of a large meteoroid or comet fragment, at an altitude of 5 – 10 km above the Earth's surface.source
1912January 18 (Old Style January 5) – Prague Conference: Vladimir Lenin and the Bolshevik Party break away from the rest of the Russian Social Democratic Labour Party.source
1913May 26 (May 13 O.S.) – Igor Sikorsky becomes the first person to pilot a 4-engine fixed-wing aircraft.source
1916August 17 (August 4 O.S.) – WWI: The Treaty of Bucharest is signed secretly between Romania and the Entente Powers, stipulating the conditions under which Romania agrees to join the war on their side, particularly territorial promises in Austria-Hungary.source
1916December 30 – (December 17 Old Style) – The mystic Grigori Rasputin is murdered in Saint Petersburg.source
1917September 14 (September 1 Old Style) – Russia is declared a republic by the Provisional Government.source