If once finds Wikitree's information to be correct (below), Robert would likely have been born earlier; moreover, he may never have been a monk at St. Evroult—
Origin of Name
After the Norman conquest of 1066, Malpas is mentioned in the Domesday book of 1086 as belonging to Robert FitzHugh, Baron of Malpas.[3]
Malpas and Earl Hugh "Lupus" d'Avranches
After the Norman conquest of 1066, Malpas is mentioned in the Domesday book of 1086 as belonging to Robert FitzHugh, Baron of Malpas. [3]
"About 1085, Earl Hugh settled the Lordship of Malpas (mostly a landlord's income stream, not actual possession of land) on his base son Robert FitzHugh. To mitigate this intrusion on the Baron of Malpas, Hugh gave one of his base daughters (Tanglust) as wife to William II, the eldest son of Sir William of Malpas. The two families (Robert fitz Hugh and the son of Sir William) continued their cordial relationship into the next generation, when a daughter (Mabel) of Robert married William III of Malpas."[4]
The Great Doomsday Book, which was started in 1086, says Robert fitzHugh held 38 distinct properties in Cheshire (one actually in Wales), as tenant in chief,[5] ie, of the king.
Its record for Malpas says,
"The same Robert holds Depenbech [Malpas]. (Earl interlined) Edwin held it. There [are] 8 hides that pay geld. The land is for 14 ploughs. In demesne are three [ploughs] and 1 bordar and ½ acre of meadow. Of this land 5 knights (milites) hold 5½ hides of Robert, and have there 3 ploughs, and 7 villeins with 2½ ploughs. There [are] 2 acres of meadow. T.R.E the whole was worth £11 4s. It was afterwards waste. Now, all included, it is worth 52s. It has 2 leagues in length and 1 in width."[6]
Robert de Malpas and Robert FitzHugh may be the same person.
3. David, born, say, 1090, (married his first-cousin, Margaret ferch Ralph ap Sir William). Wolcott states that this David's children have been erroneously given to Dan David, who had only daughters. [4]
4. William, born, say, 1120 [4]
5. David, born, say, 1150 [4]
6. William, born, say, 1180, ap David ap William ap David ap William II ap Sir William [4]had children with his mistress Beatrix, daughter of Robert de Montalt, seneschal to the Earl of Chester.[9] The earliest records of Robert de Mantalt do not name such a daughter.
https://www.wikitree.com/wiki/Space:Malpas_Barons_in_Cheshire#Origi...
