Signed Treaty of Westminster, 1153. Conquered part of Cardigan, 1157. Defeated by Rhys ap Gruffudd, c1159. Refused Archbishop Becket's claim for homage for Tonbridge Castle, 1163 (Concise dictionary of national biography, part 1 : from the beginnings till 1900. London : Oxford U. Press, c1969, pg. 242).
One LDS file has his mother as Alice (Alicia) Des Meschines, with ancestors for her listed. I give precedence to the WWW Directory of Royal Genealogical Data, which has his mother as Adeliz de Keveliock.
Roger succeeded to his title at the death of his older brother, Gilbert, in 1153.
In 1157, Roger obtained permission from King Henry II to take all the lands in Wales that he could win, and marched into Cardiganshire and captured the castles there. He called the "Good Earl of Hertford."
In 1163, Roger was summoned by Thomas Becket, the Archbishop of Canterbury, to Westminster, and he refused, claiming that holding his property because of military service, it belonged to the crown than to the church.
After his death, Matilda married William d'Aubigny, the Earl of Arundel, and had two ore children. (findagrave.com)