It’s odd how names echo through history. Prince John was made Count of Mortain in 1189 when he married Isabella of Gloucester shortly before his brother Richard went off to the Crusades. The move was designed to ensure that John towed the line whilst Richard was away.
The title and territory belonged to the Dukedom of Normandy and seems to have been given to family members. William the Conqueror made his half brother Robert the Count of Mortain in about 1063. William of Jumièges records that William of Normandy appointed his brother to the plum title after he stripped his cousin William Wernlenc of the position. The Orderic Vitalis tells the story of Wernlenc promising an impoverished household knight all the booty he could wish for from inside Normandy. It smacked of treachery so William deposed Wernlenc. Mortain was on Normandy’s border with Brittany and Maine. William needed to trust the man in charge of the territory.
William and Robert shared a mother, Herleva. William’s mother was eventually married to Herluin, Vicomte of Conteville. Odo was born in 1030, two years (ish) after William’s birth. The year after that Robert was born. William of Malmesbury’s Gesta Regnum talks about Odo being astute and clever whilst Robert was dull and plodding – though I agree with Goulding’s analysis that it would have been unwise of Duke William to place such a man in charge of the vulnerable western border to Normandy.
Robert married Matilda de Montgommery, the daughter of Roger de Montgommery who would become the Earl of Shrewsbury. The Orderic Vitalis identifies Robert’s wife and parentage.
Popular history tends to remember Odo because of his role in commissioning the Bayeux Tapestry – who can forget the club wielding bishop? Robert was not only one of William’s companions but also helped his half brother to build and equip the invasion fleet. He provided 120 vessels. He appears on the Bayeux tapestry along side William as depicted in the image at the start of the post. William of Poitiers confirms that Robert was part of the invasion planning council. Once the conquest of England was complete Robert was also made Earl of Cornwall and richly rewarded.
One key land holding was Pevensey and another was Berkhamstead. Both locations were equipped with motte and bailey castles. It is from the Orderic we discover that Robert was a key military commander when the Danes attempted to invade England in 1069 following Edgar the Athling’s rebellion. Robert was left at Lindsey to flush out the Danes whilst William went north. The Vitalis goes on to describe the “harrying of the North.”
Robert remained loyal to William throughout his half-brother’s life. William died in 1087 – by then Odo was not only disgraced but imprisoned. William wished to exclude the bishop from his deathbed amnesty but was persuaded by Robert to include their sibling.
In 1088, however, he joined with his brother Odo in revolt against their nephew William Rufus. William Rufus returned the earldom of Kent to Odo but it wasn’t long before his uncle was plotting to make Rufus’s elder brother, Robert Curthose, king of England as well as Duke of Normandy. Rufus attacked Tonbridge castle where Odo was based. When the castle fell Odo fled to Robert in Pevensey. The plan was that Robert Curthose’s fleet would arrive there, just as William the Conqueror’s had done in 1066. Instead, Pevensey fell to William after a siege that lasted six weeks.
William Rufus pardoned his uncle Robert and reinstated him to his titles and lands. He died in Normandy in 1095.
Golding, Brian. (1979) “Robert of Mortain,” in Proceedings of the Battle Conference
edited by Marjorie Chibnall (pp119-145)