1820s

The 1820s was the decade that began on January 1, 1820 and ended on December 31, 1829.

Events 
 Greek War for Independence
 Much of South America declares independence from Spain.

World leaders 
 Emir Dost Mohammad Khan (Afghanistan)
 Supreme director José Rondeau (Argentina)
 Acting supreme director Juan Pedro Julián Aguirre y López de Anaya (Argentina)
 President Bernardino Rivadavia (Argentina)
 President Vicente López y Planes (Argentina)
 General Manuel Dorrego (Argentina)
 General Juan Manuel de Rosas (Argentina)
 Emperor Francis II (Austria)
 Chancellor Klemens Wenzel von Metternich (Austria)
 Sheikh Sulman ibn Ahmad Al Khalifah (Bahrain)
 Sheikh Khalifah ibn Sulman Al Khalifah (Bahrain)
 Administrative leader Tendzin Drugdra (Bhutan)
 Administrative leader Choki Gyaltshen (Bhutan)
 President Simón Bolívar (Bolivia)
 President Antonio José de Sucre (Bolivia)
 President José María Pérez (Bolivia)
 President José Miguel de Velasco (Bolivia)
 President Pedro Blanco (Bolivia)
 President Andrés de Santa Cruz (Bolivia)
 Emperor Pedro I (Brazil)
 Sultan Muhammad Kanzul Alam (Brunei)
 Sultan Muhammad Alam (Brunei)
 Sultan Omar Ali Saifuddin II (Brunei)
 King Ang Chan II (Cambodia)
 President Bernardo O'Higgins (Chile)
 President Agustín Eyzaguirre (Chile)
 Provisional triumvirate of the three provinces Congreso de Plenipotenciarios (Chile)
 Interim Supreme Director Ramón Freire (Chile)
 Acting Supreme Director Diego José Benavente (Chile)
 President Manuel Blanco Encalada (Chile)
 President Francisco Antonio Pinto (Chile)
 President Francisco Ramón Vicuña (Chile)
 President José Tomás Ovalle (Chile)
 Emperor Daoguang (China)
 President Simón Bolívar (Greater Colombia)
 King Frederick VI (Denmark)
 Governor Muḩammad ‘Alī (Egypt)
 Emperor Iyoas II (Ethiopia)
 Emperor Gigar (Ethiopia)
 Emperor Baeda Maryam III (Ethiopia)
 President José Cecilio del Valle (Federal Republic of Central America)
 President Manuel José Arce (Federal Republic of Central America)
 President José Francisco Barrundia (Federal Republic of Central America)
 King Louis XVIII (Restoration France)
 King Charles X (Restoration France)
 Governor Ioannis Kapodistrias (Greece)
 King Henri Christophe (Haiti)
 President Jean Pierre Boyer (Haiti)
 Pope Pius VII
 Pope Leo XII
 Shogun Tokugawa Ienari (Japan)
 Khan Omar Beg (Kokand)
 Khan Mohammed Ali (Kokand)
 Emperor Sunjo (Korea)
 Emir Jaber I Al-Sabah (Kuwait)
 Emperor Agustín de Iturbide (Mexico)
 President Guadalupe Victoria (Mexico)
 President Vicente Guerrero (Mexico)
 President José María Bocanegra (Mexico)
 President Pedro Vélez (Mexico)
 Sultan Slimane (Morocco)
 Sultan Abderrahmane (Morocco)
 Fath Ali Shah of Qajar dynasty (Persia)
 King Frederick William III (Prussia)
 Emperor Alexander I (Russia)
 Emperor Nicholas I (Russia)
 King Victor Emmanuel I (Sardinia)
 King Charles Felix (Sardinia)
 King Rama II (Siam)
 King Rama III (Siam)
 King Ferdinand VII (Spain)
 Pasha Yusuf Karamanli (Tripoli)
 King George IV (United Kingdom)
 King William I (United Kingdom of the Netherlands)
 President James Monroe (United States)
 President John Quincy Adams (United States)
 Emperor Minh Mang (Vietnam)

Births 
 Clara Barton
 Louis Pasteur

Deaths 
 Carl Maria Von Weber
 Thomas Jefferson
 John Adams

Notes