The first castle on this site dates from soon after the Norman invasion and was built to control newly conquered Welsh territory and defend the English borderlands from Welsh raiders. A motte or man-made mound was created within an existing earth rampart and topped with a timber tower. In the 12th century this wooden castle was rebuilt in stone, with a fine cylindrical keep ? the castle?s most striking feature ? on top of the motte.
Recent documentary research and excavations have revealed that Longtown has Roman origins, and that the stone castle, long thought to date from the early 13th century, was probably built in the 1150s.
Longtown Castle had its origins nearly 2,000 years ago as a Roman fort, probably used by a 500-strong cohort of infantry. They had been sent to fight against a British tribe called the Silures, who were resisting Roman rule. Longtown was one of a group of forts built in the 1st century, each a day?s march from the next, along the front line with the upland tribes who were fighting to retain their independence. It had a square embankment of turf, surrounded by a ditch and topped with a wooden stockade.