Having failed in this, he settled in the village of Boulogne, close to Paris, with his twin brother the abbot Charles-Godefroy de La Trémoille.

Talmont was arrested on 20 May by the municipality of Noyant-sous-le-Lude, and sent from there to Baugé, then transferred to a prison in Angers; the Committee of Public Safety was informed of his confinement there.

Chambon, a member of The Mountain, was designated to interrogate the prince and, under the pretext of bringing him back to Paris, to deliver him to the Vendeans.

At the victory in Nantes, on 28 June 1793, Talmont proved his courage along with Jacques Cathelineau and Maurice d'Elbée, by checking the ranks, bringing back to combat discouraged Vendéens and by being wounded whilst leading the charge of the royal cavalry.

During the crisis in which the army of Vendée was pushed back towards the Loire, the Prince of Talmont was detached with 4,000 royalists to guard the Saint-Florent post.

In the council, Talmont opposed the resolution of entering Vendée, thinking it better to head to Saint-Malo, where they could receive aid promised by the English.

Taking the town depended on the issue of Francis Rawdon-Hastings' expedition, in charge of helping the royalists, who was one day before sailing from England to Jersey.

"They had only chartered," they said, "a fishing boat for Jersey, in order to hasten the arrival of help from England, and to save some women."

He joined with Henri de La Rochejaquelein who had crossed the river at Ancenis with the other chiefs, and came to find his troops at Blain to bring them back.

He considered himself free of any obligations and left through Derval, La Guerche and the Pertre forest to join Jean Chouan or to head to the coast.

On 31 December 1793, in the village of Malagra, Talmont was walking through fields near Laval and Fougères, in the company of three men, dressed as a peasant, when he stumbled upon the national guard of La Bazouge-du-Désert.

He arrived there almost dying, was subject to a new interrogation which he refused to sign, and waited to be trialed in front of the National Convention.

He was immediately sentenced to death, protested the following day and asked for a transfer to Paris having ideas of general pacification to present.

His head was subject to different desecration, it was placed on a chandelier by Jean-Louis Guilbert, former priest and member of the revolutionary commission, then it was put on a pike and exposed over the gates of the Laval castle.