Du Guesclin's career
Bertrand du Guesclin, who invaded Jersey in 1373, was born at the Chateau de la Motte de Broen in Broons, near Dinan, in Brittany. His family was of minor Breton nobility, the seigneurs of Broons.
War of Succession
He initially served Charles of Blois in the Breton War of Succession (1341-1364). Charles was supported by the French crown, while his rival, Jean de Montfort, was allied with England. Du Guesclin was knighted in 1354, after countering a raid by Hugh Calveley on the Castle of Montmuran. In 1356-1357 he defended Rennes against an English siege by Henry of Grosmont, using the guerrilla tactics that were to become his trademark. Though the siege was ended by payment of 100,000 crowns, the brave resistance helped restore French pride after the Battle of Poitiers, and du Guesclin came to the attention of the Dauphin, later Charles V of France.
When he became King in 1364, Charles sent Du Guesclin to deal with Charles II of Navarre, who hoped to claim the Duchy of Burgundy, which Charles hoped to give to his brother, Philip. On 16 May he met Navarrese forces under the command of Jean de Grailly, at Cocherel, and proved his ability in pitched battle by routing the enemy. The victory forced Charles II into a new peace with the French king, and secured Burgundy for Philip.
Battle of Auray
On 29 September 1364, at the Battle of Auray, du Guesclin and Charles of Blois were heavily defeated by John V, Duke of Brittany and the English forces under Sir John Chandos. Charles was killed in action, du Guesclin was captured and ransomed by Charles V for 100,000 francs.
In 1366 the King placed him at the head of the 'free companies', the marauding soldiers who pillaged France after the Treaty of Brétigny, and sent him to Spain to aid Henry II of Castile against Pedro of Castile. Though successful in the campaign of 1366, Henry's army was defeated 1367 by Pedro's forces, now commanded by Edward, the Black Prince, at Nájera. Du Guesclin was again captured, and again ransomed by Charles V, who considered him invaluable. In 1369, Henry of Trastamara won the battle of Montiel, gaining him the throne of Castile.
War with England
War with England was renewed in 1369, and Du Guesclin was recalled from Castile in 1370 by Charles V, who had decided to make him Constable of France, the country's chief military leader. By tradition this post was always given to a great nobleman, not to someone like the comparatively low-born Du Guesclin, but Charles needed someone who was an outstanding professional soldier. In practice Du Guesclin had continual difficulties in getting aristocratic leaders to serve under him, and the core of his armies were always his personal retinue. He was formally invested with the rank of Constable by the King on 2 October 1370. He reconquered Poitou and Saintonge and pursued the English into Brittany from 1370 to 1374. He disapproved of the confiscation of Brittany by Charles V in 1378, and his campaign to make the duchy submit to the king was halfhearted.
An able tactician and a loyal and disciplined warrior, Du Guesclin had reconquered much of France from the English when he died of dysentery at Chateauneuf-de-Randon while on a military expedition in Languedoc. He was buried at Saint-Denis in the tomb of the Kings of France. His heart is kept at the basilica of Saint-Sauveur at Dinan.
The family of du Guesclin remained in France until the French Revolution of 1789 when a number of them were guillotined and the remainder fled for their lives.
Because of du Guesclin's allegiance to France, 20th century Breton nationalists considered him to be a 'traitor' to Brittany. During World War II, the pro-Nazi Breton Social-National Workers' Movement destroyed a statue of him in Rennes.
Today there is a statue of him in Dinan.