1750Various sources, including the Intergovernmental Panel on Climate Change, use the year 1750 as a baseline year for the end of the pre-industrial era. January 13 – The Treaty of Madrid between Spain and Portugal authorizes a larger Brazil than had the Treaty of Tordesillas of 1494, which originally established the boundaries of the Portuguese and Spanish territories in South America. January 24 – A fire in Istanbul destroys 10,000 homes.
1892In Samoa, this was the only leap year spanned to 367 days as July 4 repeated. This means that the International Date Line was drawn from the east of the country to go west. January 1 – Ellis Island begins accommodating immigrants to the United States. February 1 – The historic Enterprise Bar and Grill is established in Rico, Colorado. February 27 – Rudolf Diesel applies for a patent, on his compression ignition engine (the Diesel engine). February 29 – St. Petersburg, Florida is incorporated as a town.
1886January 1 – Upper Burma is formally annexed to British Burma, following its conquest in the Third Anglo-Burmese War of November 1885. January 5–9 – Robert Louis Stevenson's novella Strange Case of Dr Jekyll and Mr Hyde is published in New York and London. January 16 – A resolution is passed in the German Parliament to condemn the Prussian deportations, the politically motivated mass expulsion of ethnic Poles and Jews from Prussia, initiated by Otto von Bismarck.
1875January 1 – The Midland Railway of England abolishes the Second Class passenger category, leaving First Class and Third Class. Other British railway companies follow Midland's lead during the rest of the year (Third Class is renamed Second Class in 1956). January 5 – The Palais Garnier, one of the most famous opera houses in the world, is inaugurated as the home of the Paris Opera. January 12 – Guangxu becomes the 11th Qing dynasty Emperor of China at the age of 3, in succession to his cousin.
1906January 12 – Persian Constitutional Revolution: A nationalistic coalition of merchants, religious leaders and intellectuals in Persia forces the shah Mozaffar ad-Din Shah Qajar to grant a constitution, and establish a national assembly, the Majlis. January 16–April 7 – The Algeciras Conference convenes, to resolve the First Moroccan Crisis between France and Germany. January 22 – The strikes a reef off Vancouver Island, Canada, killing over 100 (officially 136) in the ensuing disaster.
April 12240 – Shapur I becomes co-emperor of the Sasanian Empire with his father Ardashir I. 467 – Anthemius is elevated to Emperor of the Western Roman Empire. 627 – King Edwin of Northumbria is converted to Christianity by Paulinus, bishop of York. 1012 – Duke Oldřich of Bohemia deposes and blinds his brother Jaromír, who flees to Poland. 1204 – The Crusaders of the Fourth Crusade breach the walls of Constantinople and enter the city, which they completely occupy the following day.
1887January 11 – Louis Pasteur's anti-rabies treatment is defended in the Académie Nationale de Médecine, by Dr. Joseph Grancher. January 20 The United States Senate allows the Navy to lease Pearl Harbor as a naval base. British emigrant ship Kapunda sinks after a collision off the coast of Brazil, killing 303 with only 16 survivors. January 21 The Amateur Athletic Union (AAU) is formed in the United States. Brisbane receives a one-day rainfall of (a record for any Australian capital city).
1737January 5 – Spain and the Holy Roman Empire sign instruments of cession at Pontremoli in the Grand Duchy of Tuscany in Italy, with the Empire receiving control of Tuscany and the Grand Duchy of Parma and Piacenza, in return for Don Carlos of Spain being recognized as King of Naples and King of Sicily. January 9 – The Empires of Austria and Russia enter into a secret military alliance that leads to Austria's disastrous entry into the Russo-Turkish War.
1726January 23 – (January 12 Old Style) The Conventicle Act (Konventikelplakatet) is adopted in Sweden, outlawing all non-Lutheran religious meetings outside of church services. January 26 – The First Treaty of Vienna is signed between Austria, the Holy Roman Empire and Spain, creating the Austro-Spanish Alliance in advance of a war against Great Britain. January 27 – On its maiden voyage, the Dutch East India Company frigate Aagtekerke departs from the Dutch Cape Colony on the second leg of its journey to the Dutch East Indies and is never seen again.
April 4503 BC – Roman consul Agrippa Menenius Lanatus celebrates a triumph for a military victory over the Sabines. 190 – Dong Zhuo has his troops evacuate the capital Luoyang and burn it to the ground. 611 – Maya king Uneh Chan of Calakmul sacks rival city-state Palenque in southern Mexico. 801 – King Louis the Pious captures Barcelona from the Moors after a siege of several months. 1268 – A five-year Byzantine–Venetian peace treaty is concluded between Venetian envoys and Emperor Michael VIII Palaiologos.