Philip determined to strike the first blow, and, before the conclusion of the truce, to regain possession of Calais. This town was commanded by a Lombard officer named Almeric of Pavia. Free communication existed, in consequence of the truce, between Calais and the surrounding country, and Jeffrey de Charny, the Governor of St. Omer, and one of the commissioners especially appointed to maintain the truce, opened communications with the Lombard captain. Deeming that like most mercenaries he would be willing to change sides should his interest to do so be made clear, he offered him a large sum of money to deliver the castle to the French.
The Lombard at once agreed to the project. Jeffrey de Charny arranged to be within a certain distance of the town on the night of the 1st of January, bringing with him sufficient forces to master all opposition if the way was once opened to the interior of the town. It was further agreed that the money was to be paid over by a small party of French who were to be sent forward for the purpose of examining the castle, in order to insure the main body against treachery. As a hostage for the security of the detachment, the son of the governor was to remain in the hands of the French without, until the safe return of the scouting party.
Several weeks elapsed between the conclusion of the agreement and the date fixed for its execution, and in the mean time the Lombard, either from remorse or from a fear of the consequences which might arise from a detection of the plot before its execution, or from the subsequent vengeance of the English king, disclosed the whole transaction to Edward.
The king bade him continue to carry out his arrangements with De Charny, leaving it to him to counteract the plot. Had he issued orders for the rapid assembly of the army the French would have taken alarm. He therefore sent private messengers to a number of knights and gentlemen of Kent and Sussex to meet him with their retainers at Dover on the 31st of December.
Walter was one of those summoned, and although much surprised at the secrecy with which he was charged, and of such a call being made while the truce with France still existed, he repaired to Dover on the day named, accompanied by Ralph and by twenty men, who were all who remained capable of bearing arms on the estate.
He found the king himself with the Black Prince at Dover, where they had arrived that day. Sir Walter Manny was in command of the force, which consisted in all of three hundred men-at-arms and six hundred archers. A number of small boats had been collected, and at mid-day on the 1st of January the little expedition started, and arrived at Calais after nightfall.
In the chivalrous spirit of the times the king determined that Sir Walter Manny should continue in command of the enterprise; he and the Black Prince, disguised as simple knights, fighting under his banner.
In the mean time a considerable force had been collected at St. Omer, where a large number of knights and gentlemen obeyed the summons of Jeffrey de Charny. On the night appointed they marched for Calais, in number five hundred lances and a corresponding number of footmen. They reached the river and bridge of Nieullay a little after midnight, and messengers were sent on to the governor, who was prepared to receive them. On their report De Charny advanced still nearer to the town, leaving the bridge and passages to the river guarded by a large body of cross-bowmen under the command of the Lord de Fiennes and a number of other knights. At a little distance from the castle he was met by Almeric de Pavia, who yielded his son as a hostage according to his promise, calculating, as was the case, that he would be recaptured by the English. Then having received the greater portion of the money agreed upon, he led a party of the French over the castle to satisfy them of his sincerity. Upon receiving their report that all was quiet De Charny detached twelve knights and a hundred men-at-arms to take possession of the castle, while he himself waited at one of the gates of the town with the principal portion of his force.
No sooner had the French entered the castle than the drawbridge was raised. The English soldiers poured out from their places of concealment, and the party which had entered the castle were forced to lay down their arms. In the mean time the Black Prince issued with a small body of troops from a gate near the sea, while De Manny, with the king under his banner, marched by the sally-port which led into the fields. A considerable detachment of the division was dispatched to dislodge the enemy at the bridge of Nieullay, and the rest, joining the party of the Black Prince, advanced rapidly upon the force of Jeffrey de Charny, which, in point of numbers, was double their own strength.
Although taken in turn by surprise, the French prepared steadily for the attack. De Charny ordered them all to dismount and to shorten their lances to pikes five feet in length. The English also dismounted, and rushing forward on foot a furious contest commenced. The ranks of both parties were soon broken in the darkness, and the combatants separating into groups, a number of separate battles raged around the different banners.