 Ring of Iron

The Ring of Iron or Iron Ring of Castles was a chain of fortifications and castles built in north Wales at Edward I's command  after the death of Llywelyn ap Gruffudd in 1282 and the subsequent Conquest of Wales by Edward I of England .Edward spent over 80,000 pounds on all of the castles, with 20,000 being incurred just by Rhuddlan Castle, Aberystwyth Castle, Flint Castle, and Builth Castle .