Caus Castle is situated up on the eastern foothills of the Long Mountain guarding the route from Shrewsbury, Shropshire to Montgomery, Powys on the border between England and Wales at at Grid reference SJ340076.

The early outer earthworks of the site are probably an Iron Age fort, while the later motte-and-bailey is of Norman construction.

Roger le Corbet (or Fitz Corbet) was granted several manors in Shropshire in 1069 by William the Conquerer as the Barony of Caus for his role in the invasion of England. They were named after Roger's Normandy estate in the Pays de Caux. The Corbets owed fealty to Roger de Montgomery, Earl of Shrewsbury to help control the borders of Wales with absolute control over their demesne. Caus Castle was built by Roger le Corbet in the late 11th century as a high motte with a very small summit on which stood a tower and a strongly defended inner bailey.

The castle was sufficiently important that the Crown took an interest in its maintenance. Henry II of England had it garrisoned in 1165. In 1198 Roger Corbet re-built the tower, keep and curtain wall in stone. During the late 12th century a town or borough was founded in the large outer Bailey. A royal grant of 50 marks was made in 1263 towards further building work, when D-shape towers were added to the curtain wall. On the death of Beatrice Corbet in 1347 Caus passed to the Earl of Stafford.

Caus was garrisoned by the Seneschal Griffith ap Ieuan ap Madoc ap Gwenwys against the rebellion of Owain Glyndŵr in the 1400's, but following calls from Welsh graduates in law and students in the University of Oxford he changed sides and supported Glyndŵr. As a result his family lands and role at Caus Castle were forfeited in 1404, only to be restored by Henry V of England in 1419 after his sons Ieuan ap Griffith and Sir Griffith Vaughan captured John Oldcastle for Lord Charlton of Powis. Prior to the main conflict in the Wars of the Roses, in 1443 Sir Griffith Vaughan (or Gruffydd Fychan), Ieuan ap Griffith and their tenants murdered Sir Christopher Talbot, son of John Talbot, 1st Earl of Shrewsbury and champion tilter of England, at Caus Castle for which their family lands were again forfeited, this time to Henry VI of England. The Earl of Stafford rarely used the castle in the 15th and 16th centuries so that it decayed, and was finally deserted after it was destroyed in 1645.

References

• Barker, P.A. (1981). Caus Castle and Hawcocks Mount Archaeological Journal Vol138 p34
• Chitty, L. F. (1954). Caus Castle The Hundred-and-First Annual Meeting: Programme, CAA p19-21
• Williams G. (1998). Sir Gruffydd Fychan (?-1447) Montgomeryshire Collections Vol 86, p17-28