The Ramnulfid counts of Poitou and dukes of Aquitaine, whose vast duchy passed through the great heiress Eleanor of Aquitaine to the crowns of France and then England.
The Ramnulfids emerged in the ninth century as counts of Poitou, taking their name from Ramnulf I. As Carolingian central authority collapsed, they built a great territorial principality in the south-west, uniting Poitou with the duchy of Aquitaine and lands stretching toward Gascony. By the tenth and eleventh centuries the dukes of Aquitaine were among the most powerful princes of France, nominal vassals of the Capetian kings but effectively independent rulers of a rich, distinct region with its own language and culture.
Their court at Poitiers became a centre of the new vernacular poetry, and Duke William IX is the earliest troubadour whose verse survives — founder of a courtly literary tradition that spread across Europe.
The line ended in the male line with William X, who died in 1137 leaving his teenage daughter Eleanor as the greatest heiress in western Europe. Within weeks she was married to the heir to the French throne, and as queen of Louis VII she brought Aquitaine into the French royal orbit; she accompanied him on the Second Crusade before the marriage was annulled in 1152.
Eleanor then married Henry of Anjou, soon Henry II of England, joining Aquitaine to the sprawling Angevin dominions that ran from Scotland to the Pyrenees. Her sons Richard the Lionheart and John both ruled the duchy, and her long, turbulent life made her one of the defining figures of the twelfth century.
Through Eleanor the Ramnulfid inheritance shaped a century of Anglo-French conflict: Aquitaine remained an English possession, held of the French crown, and the tension over it helped set the stage for the Hundred Years’ War. The duchy’s wine trade through Bordeaux bound it economically to England for three hundred years.
The house of Poitiers thus vanished as a ruling line precisely by succeeding too well — its heiress carrying one of Europe’s greatest fiefs into the marriages that redrew the political map of the West.