| 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. |
| 1202–1304 | Flanders [civic and commercial buildings] | The Cloth Hall at Ypres, in Flanders (now part of Belgium), one of the finest Gothic secular buildings of the late Middle Ages, is built. It is destroyed in 1915. |
| 1254 | Germany, Russia [political events] | The Teutonic Knights (a German Christian military order) found Königsberg (modern Kaliningrad), Russia, in the heart of pagan territory. |
| c. 1254 | Venice [births and deaths] | Marco Polo, Venetian explorer who spent 17 years in China and whose Il milione/The Million (Travels of Marco Polo) has become a classic in geography, born in Venice, Venetian Dalmatia (–1324). |
| 1254 | Portugal [administration] | King Afonso III of Portugal holds the first Cortes (national assembly) attended by representatives of Portuguese towns. This is the first assembly at which the commons are represented. |
| 21 May 1254 | Holy Roman Empire, Germany, Sicily [political events] | The death of Conrad IV, Holy Roman Emperor and king of Sicily and Jerusalem, while on his way to recover control in Germany leads to an intensification of the factious dispute over succession within the royal house. He is succeeded in Sicily by his son, Conrad V (Conradin). |
| 13 July 1254 | Germany, Holy Roman Empire [political events] | A group of Rhineland towns form the Rhenish League, a confederation for mutual protection. |
| 10 October 1254 | England, Castile, León, Spain, Gascony, France [political events] | Edward Plantagenet, the son of King Henry III of England, marries Eleanor, the sister of King Alfonso X of Castile and León. This helps seal the peace between Alfonso and Henry and ensures English control of Gascony: Prince Edward is endowed with Gascony and resides there. |
| 3 November 1254 | Byzantine Empire, Latin Empire of Constantinople [political events] | The Byzantine emperor of Nicaea, John III Vatatzes, dies. He is succeeded by his son Theodore II Lascaris. Under his rule the Latin Empire is isolated and the groundwork for the recapture of its capital, Constantinople, is laid. |
| 2 December 1254 | Sicily, Italy [political events] | Manfred of Sicily, the illegitimate son of the late Holy Roman Emperor Frederick II, defeats the papal army near Foggia, Italy. He thus wins the loyalty of the Puglia region for his imperial cause. |
| 12 December 1254 | Papal States, Italy [administration] | Rinaldo Conti is elected Pope Alexander IV. |
