Raglan Castle is one of the last true castles to be built in Wales. Its construction began in the 1430s by Sir William ap Thomas, the Blue Knight of Gwent who fought at the Battle of Agincourt with King Henry V in 1415. He was responsible for building the Great Tower at Raglan, which became known as the Yellow Tower of Gwent.
After William ap Thomas’ death in 1445, the castle passed to his son William who took the surname Herbert. Sir William Herbert was a supporter of the House of York and fought at the Battle of Mortimer’s Cross in Herefordshire beside the future King Edward IV. In 1462, he became a Knight of the Garter, and in 1467 was chief justice of North Wales. In 1468, Sir William Herbert received the ultimate reward for his loyalty when King Edward IV dubbed him the Earl of Pembroke for capturing Harlech Castle, the last Lancastrian stronghold in Wales. William followed in his father’s footsteps by adding Raglan’s gatehouse, stately apartments and machicolations atop the gatehouse and Closet Tower. The machicolations, which give the architecture its French appearance, allowed defenders of the castle to drop objects onto attackers below. Construction of the castle was finally completed in 1525.
More than six decades later in 1589, during the time of William Somerset, third Earl of Worcester, the castle entered its last major phase of construction. Additions consisted of a new hammer-beam roof to the hall and long gallery on the second floor overlooking the Fountain Court.
During the English Civil War in 1646, Raglan Castle was besieged by parliamentarian forces led by Sir Thomas Fairfax. The castle was surrounded and mortar batteries (short bell shaped cannons) were dug into place. Henry Somerset who attempted to defend the castle, knew his efforts were futile and surrendered to Fairfax. As a result of the siege, the castle was heavily damaged and thus began a period of disrepair.
In 1938, Raglan Castle was placed in the guardianship of the Commissioners of HM Works by the 10th Duke of Beaufort. For two decades following the end of World War II, extensive conservation efforts were conducted to maintain the castle. Today, it is maintained by CADW (Welsh Historic Monuments) on behalf of the Secretary of State for Wales.