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Beaumaris Castle was one of the last of the ‘iron ring’ castles constructed in Wales by Edward I of England. This staggering ruin had the potential to be an even more striking fortress, however, it was left incomplete due to the sheer cost of construction. 

The ruin is open to the public today and offers a great day out for all ages. 

Who Built Beaumaris Castle?

Beaumaris was one of the many fortresses built by Edward I of England in Wales. Construction began in 1295 and its purpose was to protect the land Edward had managed to take from the Welsh. The architect in charge of construction was Master James of St George (1235-1308) who had a lot of experience building castles for the English King.

The stone used for the construction of the fortress was sourced locally. When, during the construction of the castle, costs began to sore, the decision was made to transport stone from a local limestone and sandstone source to reduce costs1 (source: World History Encyclopedia).

Why Was Beaumaris Castle Never Finished?

Beaumaris Castle was never complete due to a lack of money. The castle was simply too large and too costly to ever be completed, especially at a time when the conflict with the Scottish meant that Edward I’s money and attention were being pulled elsewhere during the construction of the castle. It is often called the ‘best castle never built’2 (source: CADW).

Beaumaris Castle Design

Beaumaris Castle is a concentric castle which means it has an outer curtain wall which surrounds and protects an inner wall. The inner section is where the accommodation would have been. The castle also had a moat around its exterior to provide further defences as well as a fortified tidal dock. This was defended by an overlooking firing platform which may have held a catapult. 


In its prime, Beaumaris Castle had a number of gates. The south gate would have opened onto the sea and would have provided more protection for the barbican. One of the gatehouses has a round arch which was perhaps a product of Master Jame’s links with Savoyard architecture.

There were gatehouses on both the outer and inner walls, however, they did not align with each other. This was a deliberate design in order to prevent attackers from being able to walk straight through both and into the heart of the castle.

If enemies managed to make it all the way through these gates they would have been faced with a firing platform located at the back of the castle. This would have allowed the defenders of the castle to prevent the attackers from gaining access to the inner walls. 

The inner gatehouses would have also held residences. The North Gatehouse had a hall on its first floor and both had a private chapel. 

The Castle Walls

The castle’s defences also include a number of towers. The outer wall had circular towers on its corners as well as two or three D-shaped ones along each side. That makes 12 towers in total.

These walls would have also had a total of 164 arrow loops which were narrow windows through which arrows could be shot at attackers. 

The inner wall also had towers on its corners as well as two large gatehouses and more D-shaped towers on either side of these. However, the towers here never reached the height they were meant to before the castle was abandoned. 

Furthermore, because the inner walls sat higher than the outer walls, those defending from the inner section of the castle had an advantage over the attackers. Archers and crossbowmen could fire from this higher position onto the enemy and prevent them from accessing the castle. 

The inner walls were 4.7 metres (15.5ft) thick and 11 metres (36ft) high. Within these impressive walls would have sat the Great Hall, stables and kitchens3 (source:  World History Encyclopedia).

Was Beaumaris Castle Ever Lived In?

Yes, although Beaumaris Castle was never fully built, it has been lived in because several parts had been completed.

In 1306, John of Metfield petitioned Edward I for funding in order to complete the castle. Over the next two decades, he worked on completing what had been left. It is unclear whether he lived in the castle. 

There would have also been a number of constables, who were placed by the King in charge of the fortress, throughout the castle’s history. The Bulkeley family resided in the castle prior to the Civil War when they were placed as the constables of the fortress. 

Was Beaumaris Castle Ever Attacked?

Beaumaris was besieged by the Welsh in 1403 led by Owain Glyndwr, however, Glyndwr’s reign did not last long and the castle was retaken by the English in 1405. During this period, the castle and the surrounding area was also subject to raids carried out by the Scottish. 

In the seventeenth century, the castle faced violence again with the outbreak of the English Civil War. The castle offered a strategic location from which the route between Ireland and the King’s residence in England could be controlled. This, therefore, made the fortress extremely valuable to both sides.

During the Civil War, the castle was originally held on behalf of the King by the Bulkeleys. However, in 1646 the castle was forced to surrender when it was surrounded by parliamentary forces. The Royalists attempted to regain the castle in 1648 but failed and were forced to surrender a second time. 

When Charles II gained the throne of England again in 1660, he reinstated the Bulkeley family as constables of the castle. 

Timeline of Beaumaris Castle

Here is a full timeline of Beaumaris Castle from its construction in the 13th century to the modern day:

1295Beaumaris Castle is built by Edward I and his architect. 
1306Construction on the castle is resumed by John of Metfield. 
1331Construction on the castle finally halts for good but it had still not reached its intended height.
1343The castle is able to withstand an attack from a Scottish force that raided Anglesey.
1403The castle is besieged (unsuccessfully) by the Welsh rebel Owain Glyndwr. 
1407Work on the town walls begins. 
1646During the English Civil War the castle is taken by parliamentary forces. The castle was originally held by the Bulkeley family who were loyal to the crown. 
1660After the Civil War, when Charles II is placed on the throne, the Bulkeley’s are given their position as constables of the castle back.
1669Portions of the town wall were demolished to improve access. Some of the wall was later demolished in the eighteenth and nineteenth century.
1926The castle passes to the state.
1986The castle earns UNESCO World Heritage Site status along with 3 other castles in North Wales

Who Owns Beaumaris Castle Now? 

The castle is owned today by CADW, the Welsh government’s historic environment service. CADW works to protect historic environments, like Castles, in Wales.

The castle is open to the public where you can climb the towers, walk along the castle walls, and enjoy the inner keep. See our full Beaumaris Castle visitor guide to plan your visit.

The castle also has UNESCO World Heritage status. This means that the UN has recognised the site as one of the world’s most significant sites which must be protected. These sites are considered of ‘outstanding value to humanity’4 (source: UNESCO).

Related Questions

What Type Of Castle Is Beaumaris Castle?

Beaumaris Castle is a concentric, stone castle.

How Big Is Beaumaris Castle?

Beaumaris Castle walls are 11m (36 feet) tall and the inner ward measures 59 x 54 metres.

Molly is Wales Guidebook's expert on castles. She has a master's degree in history and studied at Swansea University where she learnt about Welsh history and it's many castles. Molly loves to get out and explore historical buildings in person, with Oystermouth, Cardiff, and Caerphilly Castles among her favourites. When not geeking out on castles, Molly likes to spend her time reading, exploring the countryside or in the gym.