Saint Dominic (Spanish: Domingo), also known as Dominic of Osma, often called Dominic de Guzmán and Domingo de Guzmán Garcés was the founder of the Friars Preachers, popularly called the Dominicans or Order of Preachers, a Catholic religiou...

Gregory IX, Pope 1227-1241, who founded the papal Inquisition. In 1227 he excommunicated Frederick II when the emperor delayed in keeping his pledge to lead a Crusade. Gregory ordered an attack on the kingdom of Sicily in the emperor's abse...

Leonardo Pisano Bigollo or simply Fibonacci, was an Italian mathematician, considered by some "the most talented western mathematician of the Middle Ages." Fibonacci is best known to the modern world for the spreading of the Hindu-Arabic nu...

Baldwin I, the first emperor of the Latin Empire of Constantinople, as Baldwin IX Count of Flanders and as Baldwin VI Count of Hainaut, was one of the most prominent leaders of the Fourth Crusade, which resulted in the capture of Constantin...

Otto IV of Brunswick was one of two rival kings of the Holy Roman Empire from 1198 on, sole king from 1208 on, and emperor from 1209 on. The only king of the Welf dynasty, he incurred the wrath of Pope Innocent III and was excommunicated in...

Leopold VI, called the Glorious, from the House of Babenberg, was Duke of Austria from 1198 to 1230 and of Styria from 1194 to 1230. Leopold VI participated in the Reconquista in Spain and in two crusades, the Albigensian Crusade in 1212 an...

Peter II the Catholic was the King of Aragon and Count of Barcelona from 1196 to 1213. He was born in Huesca, the son of Alfonso II of Aragon and Sancha of Castile. In 1205 he acknowledged the feudal supremacy of the papacy and was crown...

Saint Francis of Assisi was an Italian Catholic friar and preacher. He founded the men's Order of Friars Minor, the women’s Order of St. Clare, and the Third Order of Saint Francis for men and women not able to live the lives of itinerant p...

Giovanni da Pian del Carpine, variously rendered in English as John of Pian de Carpine, John of Plano Carpini or Joannes de Plano, was a medieval Italian diplomat, archbishop and explorer and one of the first Europeans to enter the court of...

Ögedei Khan, also Ogotai or Oktay, was the third son of Genghis Khan and second Great Khan of the Mongol Empire by succeeding his father. He continued the expansion of the empire that his father had begun, and was the Great Khan when the Mo...

The Siege of Jerusalem took place from September 20 to October 2, 1187. It resulted in the recapture of Jerusalem by Saladin and the near total collapse of the crusader Kingdom of Jerusalem. This provoked the Third Crusade by providing it w...

Louis VIII the Lion reigned as King of France from 1223 to 1226. He was a member of the House of Capet. Louis VIII was born in Paris, France, the son of Philip II Augustus and Isabelle of Hainaut. He was also Count of Artois, inheriting the...

The Order of the Teutonic Knights of St. Mary's Hospital in Jerusalem, is a German Roman Catholic religious order. It was formed to aid Catholics on their pilgrimages to the Holy Land and to establish hospitals to care for the sick and inju...

Albertus Magnus, also known as Saint Albert the Great and Albert of Cologne, was a Dominican friar who achieved fame for his comprehensive knowledge of and advocacy for the peaceful coexistence of science and religion. He is considered to b...

Frederick II of the Hohenstaufen dynasty, was a pretender to the title of King of the Romans from 1212 and unopposed holder of that monarchy from 1215. As such, he was King of Germany, of Italy, and of Burgundy. He was Holy Roman Emperor fr...