The Hohenstaufen dynasty (ˈhoʊənʃtaʊfən, USalso-staʊ-, ˌhoːənˈʃtaʊfn̩), also known as the Staufer, was a noble family of unclear origin that rose to rule the Duchy of Swabia from 1079, and to royal rule in the Holy Roman Empire during the Middle Ages from 1138 until 1254. The dynasty's most prominent rulers – Frederick I (1155), Henry VI (1191) and Frederick II (1220) – ascended the imperial throne and also reigned over Italy and Burgundy. The non-contemporary name of 'Hohenstaufen' is derived from the family's Hohenstaufen Castle on Hohenstaufen mountain at the northern fringes of the Swabian Jura, near the town of Göppingen. Under Hohenstaufen rule, the Holy Roman Empire reached its greatest territorial extent from 1155 to 1268.
The name Hohenstaufen was first used in the 14th century to distinguish the 'high' (hohen) conical hill named Staufen in the Swabian Jura (in the district of Göppingen) from the village of the same name in the valley below. The new name was applied to the hill castle of Staufen by historians only in the 19th century to distinguish it from other castles of the same name. The name of the dynasty followed suit, but in recent decades, the trend in German historiography has been to prefer the name 'Staufer', which is closer to contemporary usage.
The name 'Staufen' itself derives from Stauf (OHG stouf, akin to Early Modern English stoup), meaning 'chalice'. This term was commonly applied to conical hills in Swabia during the Middle Ages. It is a contemporary term for both the hill and the castle, although its spelling in the Latin documents of the time varies considerably: Sthouf, Stophe, Stophen, Stoyphe, Estufin, etc. The castle was built or at least acquired by Duke Frederick I of Swabia in the latter half of the 11th century.
Members of the family occasionally used the toponymic surname de Stauf or variants thereof. Only in the 13th century would the name come to be applied to the family as a whole. Around 1215, a chronicler referred to the "emperors of Stauf".