Battle of Mortemer

Guy of Ponthieu, proclaimed that his brother's blood must be avenged. A universal jealousy raged against William amongst the baronage of Northern France. Many of the Norman barons, who, during the troubles, had found refuge at the French Court, fomented the enmity; and Henry, being thus instigated and supported by his advisers, all accomplices, he issued his general summons, not for a mere frontier inroad, but with a declared intention of subjugating Normandy, and expelling the Pirates.
Henry's summons was readily obeyed by those who assembled beneath his banner, much more in the character of allies than of vassals : or rather as expectant partners and participators in the anticipated gains.
How they poured in. They poured in from Burgundy; they poured in from Aquitain ; they poured in from Brittany; they poured in from Anjou; they poured in from Maine; they poured in from Ponthieu ; they poured in from all adjoining parts; all combining with one intent against the bated enemy. "Would not Julius Caesar himself," quoth our chronicler, "have been appalled by such an invasion ?"
Henry schemed his campaign judiciously. Assailing the Norman frontier at the most vulnerable points, he determined to effect the complete expulsion or extermination of the hated Pirates; those Pirates so detested by the French, and yet essentially French, French to the marrow of their bones; Rouen as thoroughly French, as Paris higher up upon the Seine. Henry, planned to gain Rouen by a coup de main. Henry probably reckoned on receiving support from the discontented Citizens. The Tanner's grandson could not be made sweet-he stunk in their nostrils as strongly as ever. Now came up the enemy. The royal banner waved, as the Chroniclers tell us, at the head of the levies of Gallia Celtica. Eudes, King Henry's brother, was the Commander.
William, on his part, acted warily. Caution is the surest element of conquest ; and he hovered about King Henry's camp, taking good care to avoid crossing his royal opponent's path, shunning personal conflict, lance pointed against lance, sword clashing with sword. He might be arraigned as a felon if he struck his liege Lord. But, if his liege Lord struck first, -then, blow for blow. William had greatly annoyed the royal army, cutting off the supplies. Henry could not victual his troops otherwise than by actual pillage. A commissariat was unknown, and irregular plunder enhanced the miseries of war.
The French streamed in like a rushing flood ; the conflict against the Pirates' progeny was a national enterprise ; every Norman slain, helped to pay off old scores.
The French troops began by directing their line of march through the Beauvoisin, a route which struck into the heart of the Pays de Caux, whose breezy, fragrant, undulating downs, offer such noble battle-fields.
A second division of the army, being entrusted to Eudes, the Enfant de France, he directed his course warily, having full knowledge of the people and the region, and won praise and profit by spoiling the country. A third invading flood came down from Mantes, whose "grande rue" presents that precipitous descent, which sadly, sorrowfully, and ignobly, terminated the Conqueror's earthly career. Touraine and Blois also did their duty to the King. Robert, Count of Eu, for once acting faithfully. Hugh Gournay, grim old Gournay, fierce old Gournay, the prepotent power in that region; and William Crispin and the Giffards ; and the Montforts. William was seeking to perplex the invaders, and the French were allowed to enter the Norman territory without opposition.
A large and important portion of the rebellious Baronage who have been mentioned, held extensive domains in the Pays de Bray; a rich and fertile district, which never acquired any feudal denomination. A large portion had been won by the Gournays, and old Hugh Gournay led them on.
Not apprehending danger, the French abandoned themselves to excess, pillage, and plunder, rapine and rape, and murder. The bourgade of Mortemer they occupied as head quarters. The castle rises above the surrounding country; the tall dungeon tower whose walls still crown the rock became the head station of the French troops, and they filled the fortress with the booty they had gained. The field of Mortemer, and the scattered farmhouses representing Mortemer, are standing immediately beneath that grim grey Donjon tower. The Normans diligently dogged the enemy, and when the day emerged from the night, which the French had passed in drunken debauchery, so often euphemized as merriment, they assailed the fortalice and fired the town. The dark, cavernous, antient church exists, in good repair; a score of straggling farmhouses are dotted in the surrounding pastures, and the charred timbers, turned up by the ploughshare, still testify the original extent of the town. Fierce was the conflict commencing with early dawn, "boot and saddle" pealing before the rising of the sun, whilst strife and clangour and clamour resounded throughout the day. The French, thoroughly routed, fled from the field bestrewed with corpses, every pit and dungeon was crowded with captives, and amongst them, the Count of Burgundy, his ransom worth a King's.
William, however, could not take any personal share in this important conflict. He was employed in blockading King Henry, and the news was fantastically announced to his opponent. During the darkness of the night, bold old Roger de Toeny repaired to the rising ground which commanded the French encampment; there he climbed a tree, and grimly proclaimed to the French their shame and misfortune. The suddenness of the spectral warning terrified King Henry, and he purchased a shufing retreat, by concluding a discreditable pacification. Special negociations ensued, relating to the liberation of prisoners, whose persons constituted a valuable portion of the plunder. The French King moreover conceded that William should retain whatever profit he could extract or extort from Geofrey Martel.
With the Count of Ponthieu, Guy, or Guido, whose ancestry and pertinacity rendered him the most formidable amongst William's foes, William also made his own terms. His keen conception and prophetic judgment had disclosed to him the advantages which would result to a Duke of Normandy, by obtaining the superiority of that shore, so ample and commanding in its tidal stream.
Guido was now kept hard and fast in the filthy dungeon pit, so often the facile descent into the grave. Here he pined in duresse until he consented to become William's vassal; and, surrendering his County to Normandy's Coronal, was content to receive his territory from the Suzerain's hand.
The service of a hundred knights must Guido render to the Norman Victor. An enormous burden, ten times the tale claimed from the Norman Duchy by the Capetian Monarchy. High renown resulted to William, already William the Conqueror. His success was rendered very important by the positive acquisition of the territory, but far more as displaying to the world, the power which the predestined Lord and Master of England had obtained. --Palgrave