The bishop, however, altered his mind, and proposed, in return for the fifteenth granted by the laity, to serve one year with 2,500 men-at-arms and 2,500 mounted archers. His offer being accepted, William de Beaucham was appointed his lieutenant, and in the month of May, 1383, he carried a body of troops, and numerous volunteers, to Calais, where he awaited the arrival of his lieutenant with the remainder of the forces. These were delayed, it was alleged by the design of John of Gaunt, and the bishop had no alternative but to employ his headstrong and impatient crusaders. Gravelines was assaulted, and carried. Dunkirk immediately surrendered, but the Count of Flanders, engaged in the interests of France, marched against the crusaders. Sir Hugh de Calverley had reinforced the bishop, and a battle ensued, resulting in the defeat of the enemy, and the surrender of Cassel, Dixmuyde, Bourburg, Newport, and Popperen. The King of France hastily took the field with 100,000 men, for the position appeared alarming. Norwich had also received succours, forwarded by that gallant merchant, Sir John Philpot, but the new crusaders were rogues and miscreants of the darkest stain, and were influenced by the prospect of unbounded licence and plunder. In his vexation, Spencer requested Philpot to suspend his supply of naked ruffians, but he had to put a bold face on, and match his 90,000 soldiers, crusaders, and thieves, against the army of France. There was, however, a difference of opinion, amounting to a mutiny in the army, and the mortified bishop found himself constrained to besiege Ypres. Several furious assaults were delivered, but the steady courage of the veteran garrison, posted behind strong defences, foiled the fury of the ill-conducted attacks, and the depression of defeat rested upon the army, which avenged itself by casting off all restraint, and spreading over the country for the purpose of plunder, while the pilgrims deserted in large numbers. The French army approached, and the bishop beat a hasty retreat to Dunkirk, leaving his materials of war behind. Bourburg was occupied by Sir Hugh de Calverley and Sir Thomas Trivet, and the King of France closed them in, threatening to put every man to the sword if the place was not immediately surrendered. The threat was vain, and twice the French fell on, to be bloodily repulsed, when King Charles tendered the garrison quarter, and they marched out and proceeded to Calais. From Bourburg the King carried his army to Gravelines, where he found every prospect of a tough struggle, and wisely concluded to treat rather than fight. The bishop took time to consider the terms proposed, and sent messages to King Richard for succours; but before troops could be collected and embarked, the truce expired, and, agreeable to his undertaking, the bishop dismantled Gravelines, marched the remains of his forces to Calais, and embarked for England.