On this background the Pontcallec Conspiracy took form. In the end it would be an injustice done to the Duc de Maine that would spark events. The Duc had been given leave to use his prerogatives by the will of Louis XIV but now was forced to accept that he could not. Suddenly, the Duc de Maine found himself on the side of those slighted by the Regent and shortly after rumours had it that he was planning to gather troops. Meanwhile the Marquis de Pontcallec was joined by the Comte de Noyan at the former's fortress where they planned the conspiracy against the Regent. But the these prominent names were not the only ones to set into action. An official list were drawn up by hundreds of minor nobles in Brittany and stated their grievances to the Regent. Not long afterwards the conspiring noblemen saw the opportunity of gaining a powerful ally when France and Spain declared war upon each other (the War of the Quadruple Alliance); immediately a messenger was sent to the Spanish minister in France.
However, everything had not gone unnoticed and in December 1718 the Duc and Duchesse de Maine were both arrested. This did not scare off the Marquis de Pontcallec who continued his recruitment of not only soldiers but also other noblemen. Fearing that he would also be arrested he gathered 200 supporters but no royal guards came to take him away. By July 1719 the situation was considered potentially dangerous enough to inform the Regent himself. For the conspirators good news came when the Spanish offered their support to throw over Philippe, Duc d'Orlèans and replace him with either the Spanish King Philip V or even the Duc de Maine himself.
|Plaque commemorating the Pontcallec Conspiracy|
The operation took a leap from being secretive to openly opposing the taxation when royal employees were sent to collect taxes and were met by peasants led by Rohan de Pouldu who forced the royal men back. That was the last drop for the Regent. 15.000 soldiers were sent out under Pierre de Montesquiou and entered Rennes. The entire plot was revealed when a conspirator was arrested and confessed everything. It all happened too fast for the Marquis de Pontcallec who never managed to arrange his defences - and that was it. Even the 2000 soldiers sent by the Spanish had to realize that there was little they could do against the 15.000 royal French men. In the end the Marquis de Pontcallec was betrayed and arrested four days after Christmas eve 1719.
Philippe, Duc d'Orlèans established a special Board of Justice at Nantes simply to try those implicated in the conspiracy. Considering that it was the second conspiracy against him something had to be done - the first conspiracy had ended in a pardon for all involved. In total 23 men were tried (16 in absentia since they had fled) and of the remaining seven men four was condemned to death. These were: the Marquis de Pontcallec and the noblemen Montlouis, Du Couëdic and Talhouët. They were all beheaded immediately after the sentence.
After the trial most of France was shocked at how severe the consequences had been for the conspirators (perhaps in light of the previous convictions?). However, it was not just the minor nobles who had learned a lesson. The extra taxation was dropped and all the land and money that had been confiscated was given back. However, those who had fled was not allowed to return to France till after 10 years.