and John of Gaunt, sons of Edward III. The years 1351–1352 he spent on crusade in Prussia. Here he quarrelled with Otto, Duke of Brunswick. This almost led to a duel between the two men in Paris, which was only averted by the personal intervention of the French king. 1356 Normandy In 1355 full-scale war between England and France flared up again. By 1356 money and enthusiasm for the war were running out in France. The modern historian Jonathan Sumption describes the French national administration as "fall[ing] apart in jealous acrimony and recrimination". Much of the north of France was openly defying John and a contemporary chronicler recorded "the King of France was severely hated in his own realm". Arras rebelled and its citizens killed loyalists. The major nobles of Normandy refused to pay taxes. On 5 April 1356 they were dining at the table of John's eldest son (the ), Charles, when John arrived, accompanied by armed men, and arrested ten of the most outspoken; four were summarily executed. One of those imprisoned was the notoriously treacherous Charles of Navarre, one of the largest landholders in Normandy. The Norman nobles who had not been arrested, sent to Navarre for reinforcements. On receiving news of this, Louis began raising troops. The Norman nobles also turned to Edward for assistance. John's army took control of most of Normandy and laid siege to those rebel-held fortifications which refused to surrender. John's son Charles, who as well as being the was the Duke of Normandy, took charge of suppressing these holdouts. Navarre's partisans negotiated an alliance with Edward. The English had been preparing an expedition to Brittany under Grosmont, as part of the War of the Breton Succession. Edward diverted this to Normandy to support the French rebels. On 1 June 1356 an initial force of 140 men-at-arms, 200 archers and 1,400 horses left Southampton in 48 ships for the beaches near St. Vaast la Hogue in the north-east Cotentin. Horses transported in the ships of the day needed several days rest to recover, otherwise, they were liable to collapse, or even die, when ridden. On 18 June Grosmont arrived and brought the English strength up to 500 men-at-arms and 800 longbowmen. They were reinforced by 200 Normans under Philip of Navarre. The English commander Robert Knolles joined Lancaster in Montebourg with a further 800 men detached from English garrisons in Brittany. The