In summer 1337, with the outbreak of the Hundred Years War, he provided a contingent of 6,000 men for the campaign of Raoul I of Eu, Constable of France, in Gascony. In July 1338, he attended a general conference at La Réole, but before achieving anything of note, John and his fellow captain-general in the south, Gaston III, Count of Foix, were called north to help counter the expected invasion of Northern France by King Edward III of England. As this threat grew weaker the French offensive in the south was resumed with the siege of Penne-d'Agenais in November by John of Bohemia and the Count of Foix. John provided 1,200 men for this siege, which ended with the surrender of the town, though not the castle. Through these early years of the war the Count of Foix had conducted a series of independent campaigns which allowed him to expand his personal territory into the Adour valley and the Landes. This expansion brought him into conflict with Armagnac. Just after his return from the north at the end of 1339 John attacked Miramont-Sensacq, a small town he laid claim to, but which was situated in territory dominated by the Count of Foix. This started a short but violent private war, ended by the town taken into royal custody. This quarrel caused John to reconsider his allegiance to the French Crown. When he in May 1340 again went to join King Philip VI of France’s northern army, he left Bernard Ezi IV, Lord of Albret with documents stating terms under which terms he would be willing to do homage to Edward III. As compensation for the territory he expected to lose once he switched allegiance Armagnac demanded several towns held by the King of France, chief among them Montréal, Mézin and Condom. Of these the English only succeeded in taking and holding Mézin. The negotiations therefore came to an end and John remained a vassal of Philip VI. In the north the situation had improved for the English with their naval victory in the Battle of Sluys. Edward III’s next step was an attack on Saint-Omer by his Flemish allies led by Robert III of Artois. However Robert III failed completely in masking his intentions. This allowed Philip VI to dispatch John of Armagnac to reinforce the garrison already present there under Eudes IV, Duke of Burgundy. On 26 July what begun as an unauthorized attack on the enemy lines by some French knights developed into a major battle as the Duke of Burgundy decided to sally forth in strength. During the Battle of Saint-Omer the Count of Armagnac with his retinue of 300 heavy cavalry succeeded in breaking the Flemish left and then in the following pursuit causing several thousand casualties. Faced with the loss of the bulk of his army Robert of Artois was forced to retreat from the city in disorder. Meanwhile Edward III had with his own army laid siege to the city of Tournai. The siege dragged out and in September Philip VI marched to confront him. The result was not battle, but negotiations in which John of Armagnac took part as one of five French plenipotentiaries. The negotiations resulted in a truce concluded on 24 September. The lull in the fighting, except for an interlude in 1342, was to last until 1345. In August 1345 Armagnac was laying siege to the Anglo-Gascon garrison at Monchamp outside Condom when Henry of Gosmont, Earl of Lancaster arrived in Bordeaux. Derby’s opened his campaign with the capture of the garrison town of Bergerac by storm. This caused major shock to at the French court as no significant English army was expected in the south. Armagnac helped shore up the French position by gathering some of the survivors and retreating to Périgueux. Lancaster moved to surround Périgueux, but did not have the strength to capture the city and in October he was forced to withdraw with the arrival of a force commanded by Louis of Poitiers, Count of Valentinois. In September 1346, following the French defeat at the Battle of Crécy and the beginning of the English Siege of Calais, Armagnac was appointed royal lieutenant in the south-west. However due to the overall worsening French situation he was left with few troops and little money. He was therefore unable to stop Lancaster neither from consolidating English gains in the south nor from launching a major raid into Poitou.
Marriages & Children
Armagnac married Reine de Got, a niece of Pope Clement V, they had no children. Armagnac later married Beatrice of Clermont. They had three children:
John I of Armagnac features in the medieval series, Lions and Lilies Books 1, 2 and 4 - The Lily and the Lion, The Order of the Lily and The Traitor's Noose by Catherine A. Wilson and Catherine T. Wilson.
