Raglan Castle - one of the most impressive and well-preserved castles in Wales
as featured in The Steam Pump Jump by Jodi Taylor
An AI-generated voiceover has been added for accessibility.
In The Steam Pump Jump, Markham relates the events at Raglan Castle when they go to investigate if Edward, Lord Herbert, son of Henry Somerset, built a "water commanding machine" in the Great Tower, which used steam to pump a huge spout of water high into the air. In this history briefing, we examine the history of Raglan Castle, which remains one of Wales’s most impressive castles. Raglan continues to captivate historians, architects, and visitors alike as a reminder of Wales’s turbulent history and a monument to its enduring cultural heritage.
Raglan Castle, located in Monmouthshire, Wales, is a majestic late medieval fortress with a rich and varied history. Built in the 15th century, it is one of Wales's most impressive and well-preserved castles. With its blend of military strength and Renaissance elegance, Raglan Castle offers visitors a unique glimpse into both the defensive needs and the luxurious tastes of the Welsh nobility during the late medieval period.
Construction of Raglan Castle began in the mid-15th century under Sir William ap Thomas, the lesser son of a Welsh family who rose through the ranks of mid-15th century politics, profiting from the benefits of the local offices he held. Sir William purchased the manor of Raglan and began building the stronghold around 1435, but his son, William Herbert, expanded the castle to the grand structure that stands today. Herbert, a powerful figure in the Wars of the Roses and later the Earl of Pembroke, transformed Raglan into a symbol of wealth and prestige. He was executed as a Yorkist supporter in 1469 after the Battle of Edgecote Moor. Building work may have stopped for a period under his son, also called William Herbert, before recommencing in the late 1470s. By 1492, the castle passed to Elizabeth Somerset, William Herbert's daughter, who married Sir Charles Somerset, passing the castle into a new family line.
Raglan Castle’s construction reflects a transitional period in British castle building, where comfort and status became as important as defense. The castle features massive stone walls, corner towers, and an impressive Great Gatehouse, but its spacious living quarters, ornate windows, and expansive gardens signal a shift toward a more refined and stately way of life. Unlike earlier fortresses, which were primarily built for defense, Raglan Castle was intended to be both a stronghold and a luxurious residence for its noble occupants.
Raglan Castle’s architecture is notable for its combination of defensive features and Renaissance influences. One of its most iconic features is the massive hexagonal Great Tower, also known as the Yellow Tower of Gwent. Positioned on an artificial mound and surrounded by a deep moat, the tower provided an elevated vantage point for observing the surrounding landscape and served as the final line of defense in case of an attack.
The Great Gatehouse, another striking feature, provided the main entrance to the castle and was equipped with portcullises and drawbridges for security. Once inside, the visitor would be struck by the grandeur of the castle’s residential areas. The Fountain Court, the heart of the castle, was surrounded by luxurious living quarters, including the state apartments, great hall, and private chambers. The Renaissance influences are evident in the large, airy windows, decorative battlements, and landscaped gardens designed to reflect the prestige of the Herbert family.
Raglan Castle played a significant role during the English Civil War (1642–1651). The castle’s then-owner, Henry Somerset, the 1st Marquess of Worcester, was a staunch supporter of King Charles I and used Raglan as a Royalist stronghold. The castle became a focal point of Royalist resistance in Wales, and in 1646, it was besieged by Parliamentarian forces under Sir Thomas Fairfax.
The siege lasted nearly 13 weeks, one of the longest of the Civil War, before the castle finally surrendered in August 1646. Fairfax ordered the castle to be totally destroyed under the supervision of Henry Herbert, a descendant of William ap Thomas. However, the fortifications proved too strong, and only a few of the walls were destroyed or slighted. Historian Matthew Johnson describes the event as having the atmosphere of a "community festival", as local people dredged the castle moat in search of treasure, and emptied the fishponds of valuable carp. The castle's library, including an important collection of Welsh documents and books, was either stolen or destroyed.

Today, Raglan Castle is managed by Cadw, the Welsh government’s historic environment service, and is open to the public as a heritage site. Despite the damage it sustained during the English Civil War, the castle remains one of Wales's most well-preserved medieval sites. Its iconic Great Tower, impressive gatehouse, and sprawling grounds continue to attract thousands of visitors each year.
Visitors can explore the castle’s ruins, including the remnants of its grand halls, private chambers, and defensive structures. From the top of the Great Tower, visitors can enjoy sweeping views of the surrounding countryside. The castle also hosts various events, reenactments, and educational programs throughout the year, bringing its rich history to life for modern audiences.
Discover how Markham and Peterson fared at Raglan castle in The Steam Pump Jump by Jodi Taylor.
We hope you have enjoyed this History Briefing. Click here to read more background history to the events in The Chronicles of St Mary’s series by Jodi Taylor.