Dangereuse was born around 1079 into a noble family to parents Bartholomew de l’Isle Bouchard and his wife Gerberge in the centre of modern-day France. Unfortunately, due to the family not being extremely important and the events taking place so long ago, there is little detail on her early life. However, it seems her first name was actually Amauberge, and Dangereuse was a sobriquet that came later.
In 1109, she appeared on record, and it seems that some years before this, Dangereuse had married. Her husband was Aimery I, Viscount of Châtellerault, and he was a vassal to William IX, the Duke of Aquitaine. Dangereuse had five children with her husband; Hugh, Raoul, Amable, Aois, and Aénor.
Dangereuse, or Dangerosa as she is sometimes called, crossed paths with William IX, Duke of Aquitaine, a few years into her marriage. This was probably just an innocent meeting as the Duke was her husband’s overlord. However, Dangereuse had a reputation for not caring at all what people thought of her, and William was rather popular with women as he was a troubadour (a lyrical poet) as well as a Duke, so maybe the pair were drawn to each other during this initial meeting.
In around 1115, we begin to hear that William had kidnapped a woman called Amauberg, the wife of one of his vassals. He is said to have taken Amauberg by force to La Maubergeonne castle, which was in Poitiers, where he forced her to stay and become his mistress. Due to the name of the tower that she lived in, people called her La Maubergeonne. This sort of kidnapping was common during the medieval period, and many women suffered greatly after being kidnapped and forced into marriages. However, it is widely recorded that Amauberg was actually part of this plan all along. It seems that her husband Aimery was too afraid of the Duke to fight back, and so Amauberg and William became a long-term couple, and she began to be known as Dangereuse.
William, however, had a wife, Phillipa of Toulouse, who returned from time in her homeland to discover her husband had moved Dangereuse into their palace. Phillipa was outraged and tried her best to gather support from courtiers to have the woman removed, but nobody would back her as they had to stay loyal to their lord. A Papal legate even pleaded with William to separate from Dangereuse, but William simply mocked the legate, and Phillipa had to leave her home to live in Fontevrault Abbey, where she died in 1118.
After the death of Phillipa, Ermengarde of Anjou visited William’s court. She was his first wife, but their marriage fell apart after three years passed without any children being born to the couple. Strangely, Ermengarde and Phillipa had grown close as friends, and now with Phillipa dead, Ermengarde wished to take revenge on William for mistreating her. William ignored Ermengarde’s pleas that he remove Dangereuse from his home and restore her instead, so Ermengarde took her complaints to the pope. Pope Calixtus II heard Ermengarde’s woes at the council of Reims, and it seemed that he agreed that William should be excommunicated from the church in 1119. However, it looks like he never actually went through with this, as by 1120, William was fully readmitted into the church.
It seemed that nothing could stop Dangereuse and William from doing whatever they wished, and over the years, they had three children together called Henri, Adelaide and Sybille. William also had legitimate children with his wife Phillipa, and the relationship with Dangereuse greatly damaged the bond with his oldest son, also called William.
In order to heal the relationship with his son, Duke William arranged for his son to marry Dangereuse’s daughter from her marriage to Aimery. It is not clear why this decision was made, but supposedly this would force William to accept Dangereuse and would also be a great match for Dangereuse’s daughter as it was greatly above her rank.
In 1121, Aénor de Châtellerault, Dangereuse’s daughter, married William, Duke William’s son. The couple had three children together: Eleanor, Petronilla and William, though William died in childhood.
In 1127, William IX died, and his son became William X, Duke of Aquitaine. Nothing more was heard of his seductive mistress Dangereuse after this other than the date of her death in 1151.
The relationship between William IX and his mistress Dangereuse left its mark on history as their granddaughter (Duke William X’s daughter) became the heir to Aquitaine. She is remembered widely as Eleanor of Aquitaine, one of medieval Europe’s most powerful women. She was married to King Louis VII of France and later King Henry II England; her children went on to rule over much of Europe.