Scandalous sisters: how three French princesses brought down the Capetian dynasty

• Read more | How to be a medieval queen: the realities of being a royal woman in the Middle Ages

Between 1305 and 1308, Philippe IV’s children all married wealthy members of the nobility, which seemingly strengthened dynastic alliances. The eldest son and crown prince Louis – who by this time was king of Navarre, a kingdom between France and Spain that he had inherited from his mother – married Marguerite, heiress to the large duchy of Burgundy. The younger princes, Philippe and Charles, married sisters Jeanne and Blanche respectively: also heiresses from Burgundy. Meanwhile, the king’s daughter Isabella married across the channel, becoming wife to the English prince Edward (the future King Edward II).

While little is known about the early relationships between the three princes and their wives, what came later would have devastating consequences for the royal family.

• On the podcast | Eleanor Janega busts popular myths surrounding women in the Middle Ages

A royal scandal erupts

In early 1314, Marguerite and Blanche were accused of committing infidelity with two knights, the brothers Philippe and Gautier of Aunay, while Jeanne was implicated as she allegedly kept watch during the adulterous meetings. When the scandal erupted, Jeanne was around 25 years old while Marguerite and Blanche were young adults. The claims were certainly plausible: the Aunay brothers’ family had aligned themselves with Philippe IV’s brother, Charles de Valois, and so spent much time at court.

There are various theories about where and who these accusations came from. One motive was the power struggle taking place between the king’s influential advisor, Enguerrand de Marigny, and brother. Accusing the Aunays of treason could have been a way for Marigny to destroy Charles de Valois’ faction. The fate of the French princesses was therefore just an unfortunate by-product.

Another motive may have come from the princes themselves, none of whom had male heirs from their wives. Or there is an alternative: a misogynistic rumor stating that the charges came from the princes’ sister Isabella, who wanted to further her own son’s chances to inherit.

Regardless of the origins of the charges, Philippe IV seemingly had no trouble believing them. He swiftly had all three women arrested, with Marguerite and Blanche imprisoned in the dungeons of Château Gaillard in Normandy. Jeanne was saved this fate by her husband, Philippe, who advocated for her (the only one of the three princes to do so). She instead lived under house arrest in the Château de Dourdan.

• Read more | Doctors, playwrights and feminists: meet 6 trailblazing medieval women

At the centre of the adultery scandal were a set of coin purses. According to a story put forward by Isabella, she had allegedly gifted them to Marguerite and Blanche, but then noticed during a visit to the French court that the Aunay brothers had them. The princesses must have passed them on to their lovers, was the claim. Isabella immediately informed her father of her suspicions, and Jeanne found herself caught up in the matter.

Under torture, the Aunays confessed to the affairs and found guilty in court. Committing adultery against a person of royal blood was an act of treason, and so in April 1314 Philippe and Gautier were given bloody traitor’s deaths by being hanged, drawn, and quartered.

As for the three women, they languished in their imprisonment. Jeanne continued to be treated remarkably better than her younger sister and sister-in-law. Her husband even visited her during her trial and house-arrest. His reasoning is a matter of speculation, though it is important to note that Jeanne was the richest of the princesses and had been named as heir to the county of Burgundy since her father had no sons. Marguerite and Blanche were entirely dependent on their husbands and had no property or money to their names.

These differences in status could explain why Jeanne received different treatment. What’s more, she and her husband did have at least four surviving children in the early years of their marriage, which could indicate a bond between them.

• Read more | The French royal mistresses who made it about more than sex

A new sovereign

By the end of 1314, Philippe IV had died and his eldest son became king of France, as Louis X. Shortly afterwards, two significant changes occurred for the alleged adulteresses. The charges against Jeanne were dropped, allowing for her release and reunification with her husband; and Marguerite died suddenly in her cell in April 1315. Although rumours swirled of her being strangled so that her husband could remarry, she more likely died of sickness due to the squalid conditions of her dungeon prison – a slower, but equally ruthless murder.

Marguerite’s widower (the new king) certainly moved on quickly: Louis remarried that same year, to Clementia of Hungary, bringing renewed vigour to the mission of producing a male heir. Luck was not on Louis’s side. After a lifetime of bad health, he died the following year, survived by his pregnant wife and the young daughter he had with Marguerite, named Jeanne. Though Clementia bore a son five months later, whom she named Jean, the baby survived only five days.

What happened next set a precedent for the French royal inheritance up until the abolition of the monarchy. From Hugh Capet (who reigned 987–96 AD) to Louis X’s death in 1316, the Capetian dynasty famously enjoyed an unbroken line of male descent . Each king had a son or grandson to rule after them. With the death of Clementia’s infant son, however, there was no male heir to ascend the French throne; only Louis and Marguerite’s four-year-old daughter.

But the new regent, Louis’s elder brother Philippe was quick to push her to the side. In front of an assembly of noblemen in January 1317, he declared that “women do not succeed to the throne”, bypassed his niece’s claim and – after his infant nephew Jean died – declared himself king of France.

• Read more | The medieval women who spoke out against sexual violence

This exclusion of women continued when Philippe V died in 1322, five years later, as all four of his own daughters were ignored in favour of the last Capetian brother, Charles. The new king, Charles IV, finally annulled his marriage to the still-imprisoned Blanche and married twice more, although both failed to produce a son and heir.

When Charles IV died only six years later, in 1328, there were no more brothers to steal thrones from the French princesses. Instead, it was the turn of the cousins. The two closest male heirs were Edward III, now king of England, and Philippe of Valois, the nephew of the former king, and namesake, Philippe IV. The throne passed to the latter, thus founding the Valois dynasty.

The final Capetian kings had been so desperate for male heirs after they had imprisoned their wives, but they had never materialised. Their dynasty’s three-century hold over France dissolved. However, the line did continue outside of France. Jeanne, the daughter of Marguerite and Louis X, inherited the throne of Navarre, which had a history of ruling queens. She went on to rule for 20 years.

Poetically, her descendants would include fiery, independent queens and, eventually, Henry of Bourbon, who would be the founding member of a new dynasty when crowned as king of France in 1594.