The Hohenstaufen, also called the Staufer or Staufen, were a dynasty of German kings (1138–1254) during the Middle Ages. Besides Germany, they also ruled the Kingdom of Sicily (1194–1268). In Italian historiography, they are known as the Svevi (Swabians), since they were Duke of Swabia from 1079. Three members of the dynasty—Frederick I, Henry VI and Frederick II—were crowned Holy Roman Emperor.