This is Walter de Lasci of Longton Castle, Herfordshire. He was Sire de Lacy in England and Lord of Lassy in Normandy. He was the 1st Baron of Ludlow and Weobly. It is sometimes claimed that he fought with WILLIAM THE CONQUERER at the Battle of Hastings. There is no proof of this. The reason for this belief is the large amount of land granted to him by THE CONQUERER. An alternate possibility is that he was rewarded for outstanding service at Acre during the crusade.
From W E Wightman, "The Lacy Family in England and Normandy, 1066-1194": genealogical chart following p 260. Besides the children Roger and Hugh entered here, Wightman has "Walter, abbot of Gloucester (o.s.p. 1140)" and "Daughter".

1st Baron de Lacy by tenure, came to English with William the Conqueror in 1071, took his name from his place of origin in Normandy, the manor of Lacscy, and acquired large estates on the Welsh border, including the Lordships of Ludlow in Shropshire, Staunton Lacy and Ewyas Lacy.9