This would have included contacts with merchant shipping along the river Vie and along the coast of Poitou and Brittany with an island stronghold at Yeu.

The union was short-lived, as relatives of the ducal family – in particular, from the de Blois faction – laid a complaint with the bishops of Vannes and Rennes to protect their heritage, and an investigation was conducted on 10 February 1330, resulting in the marriage being annulled by Pope John XXII.

Jeanne, a recent widow herself of the Lord of Châteaubriant, controlled areas in Poitou just south of the Breton border from Beauvoir-sur-Mer in the west to Châteaumur in the southeast of Clisson.

Combining these assets made Jeanne and Olivier the seigneurial power (senior Lord of an area)[8] in the border region of Brittany.

Jeanne's husband Olivier and Hervé VII de Léon, the military commanders defending this city, were captured.

This led Olivier to be subsequently suspected of not having defended the city to his fullest and to be accused by Charles de Blois of being a traitor.

Under the perceived safe conditions of this truce, Olivier and fifteen other Breton and Norman lords were invited to a tournament on French soil, where he was subsequently arrested, taken to Paris and tried by his peers.

Jeanne managed to evade arrest as she was being protected by Jean de Clisson (Olivier's eldest son from his first marriage, at the time the Lord of Milly, a castle about 55 km east of Paris) and accompanied by Guilaume Bérard, Jeanne's squire and valet, Guionnet de Fay, and Guillaume Denart.

From there, his corpse was drawn to the gibbet of Paris and there hanged on the highest level, and his head was sent to Nantes in Brittany to be put on a lance over the city's Sauvetout Gate as a warning to others.

[15] This execution shocked the nobility, as the evidence of guilt was not publicly demonstrated and the process of desecrating/exposing a body was reserved mainly for low-class criminals.

[16] On 26 August 1343, for her attempted bribery of the King's sergeant, Jeanne was also charged with the crime of lèse-majesté and subsequently sentenced to banishment, with confiscation of her property.

[12] Jeanne took her two young sons, Olivier and Guillaume, from Clisson to Nantes, to show them the head of their father displayed at the Sauvetout gate.

Jeanne, enraged by her husband's execution, swore retribution against King Philip VI and Charles de Blois.

Its main intent is to destroy or disrupt the logistics of an enemy on the open seas by attacking merchant shipping rather than engaging actual combatants.

The Pointe du Raz was an especially good spot to conduct piracy since these waters were dotted with numerous small, often uninhabited islands which were ideal for ambushes.

[24][25] In the 1350s, Jeanne married for a fourth time to Walter Bentley,[26] one of King Edward III's military deputies during the campaign.

[27] [28] Raoul de Caours,[29] Edward III's Lieutenant in the neighbouring province of Poitou, had wrested control of several of Jeanne's properties from the French.

[31][32] At this point the war had come to a halt as both nations were exhausted, one of the main factors being the spread of the Black Plague which had decimated at least 20 percent of the population.

[30] Jeanne finally settled at the Castle of Hennebont, a port town on the Brittany coast, which was in the territory of her de Montfort allies.

Local tradition speaks of the "red men" or English Soldiers who came to rescue Jeanne at one stage when she had become entrapped by the French.

Another street also bears her name: Rue Jeanne de Belleville, in La Bernerie-en-Retz, in the Rogère district.