Caus Castle is a ruined hillfort and medieval castle in the parish of Westbury, Shropshire, England. It was the site of an Iron Age hillfort before being occupied by the Anglo-Saxons and then the Britons, who called it Caustow. In 874 AD, the castle was stormed by Mercian and Norse warriors led by Ivar the Boneless following the murder of Ealdorman Ceolbert, whom Ivar had murdered and then pinned his death on King Rhodri the Great, who had used Caustow as his headquarters during his 872-874 campaign in Shropshire. Rhodri was captured and then executed at the nearby Manstone Rock in the cruel "Blood Eagle" ritual, but Ivar was killed in a duel with his former ally Eivor after confessing to having killed Ceolbert and framed the Welsh. Following the Norman conquest of England, Roger le Corbet was granted several manors in Shropshire in 1069, and he built a motte and bailey castle at the site of the ruined Saxon-era fortress. King Henry II of England had it garrisoned in 1165, and a borough was built in the late 12th century. By 1349, the castle was home to 58 burgesses. It later fell into neglect due to Welsh border troubles, and it was demolished by the Parliamentarians in 1645 after having served as a minor Royalist garrison during the English Civil War.
