Longtown Castle

After the Norman invasion of England and Wales in 1066, a small castle began to be built at Pont Hendre, close to the site of the current castle, by Walter de Lacy in order to protect the river crossing there. Following Welsh attacks, Walter abandoned Pont Hendre and instead started to build a castle at Longtown, on the site of the old Roman fort. The early castle was occasionally also called Ewias Lacey, named after the wider lordship; "Ewias" was a term meaning "sheep district". Longtown Castle was designed as a motte and bailey castle, on high ground alongside the River Monnow.

The de Lacy family controlled Longtown Castle until Walter de Lacy's death in 1234. John Fitzgeoffrey then acquired the castle, during a period of increased conflict and tension between the Welsh princes Llywelyn the Great and Dafydd ap Llywelyn and the English marcher lords. The castle reverted to the de Lacy family and became part of the inheritance of Margery (or Margaret) de Lacy, daughter of Gilbert de Lacy, who had predeceased his father Walter de Lacy, Lord of Meath, and his wife Isabel Bigod, daughter of Sir Hugh Bigod, 3rd Earl of Norfolk.