| 1100–1532 | South America [administration] | The Inca empire dominates the Andes region of South America. Its population numbers as many as 12 million. Incan society is based on a strict hierarchy, with an emperor who rules with absolute power. Their religion is based on sun-worship, and they are skilled builders who create a system of roads and irrigation. |
| 1520 | Central America, Spain [food and drink] | The Spanish explorer Hernán Cortés introduces chocolate, which had been used by the Aztecs in Central America, to the Spanish, who keep its existence secret for almost a century. |
| 1520 | England, Netherlands [plays] | The morality play Everyman, based on the Dutch morality play Elckerlijk of about 1495, appears in English. |
| 1520 | Germany, Holy Roman Empire [weapons] | Nuremberg gunsmith August Kotter develops rifling for the barrels of firearms, cutting a spiral groove inside the barrel in order to spin the shot as it leaves the gun. |
| June 1520 | Mexico, Aztec Empire, Spain, Central America [colonization] | The Spanish conquistador Hernán Cortés, holding the huge Aztec capital city of Tenochtitlán in the Valley of Mexico with his small force, hears that Diego Velázquez de Cuéllar, governor of Cuba, has sent 900 troops under Panfilo Narváez to Veracruz to depose him. He takes four-fifths of his Spanish troops back towards the coast and defeats Narváez, Cuban commander, persuading most of the newcomers to join him. |
| 3 June 1520 | Aztec Empire [births and deaths] | Montezuma II (or Moctezuma), ninth Aztec emperor 1502–20, captured by Hernán Cortés, dies in Tenochtitlán (near modern Mexico City) (c. 54). |
| 7 June - 24 June 1520 | England, France [political events] | King Henry VIII of England and King Francis I of France meet in ostentation at the ‘Field of the Cloth of Gold’ between Gravelines and Ardres in Picardy, near Calais, France, and sign the marriage contract for their children Mary Tudor and the dauphin Francis. |
| 15 June 1520 - 3 January 1521 | Papal States, Italy, Holy Roman Empire, Saxony, Germany [political events] | Pope Leo X excommunicates the German church reformer Martin Luther for heresy and dissent by the bulls Exsurge Domine/Rise Up, O Lord (which Luther burns at Wittenberg on 10 December) and Decet. |
| 30 June 1520 | Mexico, Aztec Empire, Spain [colonization] | The Spanish conquistador Hernán Cortés returns, reinforced, to the Aztec capital of Tenochtitlán in the Valley of Mexico to find the force he left behind under Pedro de Alvarado besieged by Aztecs under Cuitlahuoc, following Alvarez's murder of Cuitlahuoc's predecessor, the Aztec emperor Montezuma II. The Spaniards break in and out, losing a third of their army in ‘the Bloody Night’ as they escape the city. |
| 22 September 1520 | Ottoman Empire [births and deaths] | Selim I, Ottoman sultan (1512–20), who extended the Ottoman Empire to Egypt, Syria, and the Hejaz, dies in Corlu, Ottoman Empire (c. 50). |
| 21 October - 28 November 1520 | Spain, South America [exploration] | The Spanish expedition under the Portuguese navigator Ferdinand Magellan negotiates the strait which now bears his name, between the South American continent and the island of Tierra del Fuego. Three ships reach the Pacific Ocean and continue northwest, the fourth having turned back. |
