Roger De Montgomery was in command of a wing at the Battle of Hastings but returned to Normandy with Queen Matilda and the young Duke Robert. He was head of the council that governed the Duchy of Normandy in Duke William’s absence.
The family ancestry was closely entwined either by blood or marriage with the Duchy of Normandy. Roger de Montgomery had four sons the eldest of which was Robert, Count of Alencon who was his successor. Following Robert was Hugh, Earl of Arundel and Shrewsbury, probably the main custodian of the family domains granted in England. The next youngest was Count Roger de Piotou who was made the first Earl of Lancaster by Duke William of Normandy. Philip, the youngest, accompanied Duke Robert on the first crusade to the Holy Land and died there.
Roger had contributed sixty ships to the invasion fleet and was in charge of one wing of the army at the Battle of Hastings. After the invasion and conquest Roger was responsible to William as his chief architect in the defence of the middle marches of the border in his defence against the Welsh. He built many castles including Montgomery, Shrewsbury, Arundel, Ludlow, Clun, Hopton and Oswestry.