Caernarfon Castle

Why does Caernarfon Castle matter?

Here is a question to consider: when a ruler defeats a conquered people, what do they build? They could build barracks — purely functional, utilitarian. They could build nothing at all, relying on military force alone. But Edward I built something different: castles so vast, so expensive, and so deliberately symbolic that even today, nearly seven and a half centuries later, they dominate the landscape of north Wales. Why? What were those buildings meant to say — and to whom?

Caernarfon Castle stands at the mouth of the River Seiont, on the north-west coast of Wales, in the town of Caernarfon. It is one of the most impressive medieval fortifications in Europe, and for the AQA 2026 GCSE History exam it is the historic environment site for Medieval England under Edward I. Examiners will ask questions about the castle's location, design, purpose, and what it reveals about Edward I's relationship with Wales and his broader ambitions as a ruler. This page prepares you for all of those questions.

The context: Edward I and the conquest of Wales

To understand Caernarfon, you need to understand why it was built — and that means understanding Edward I's relationship with Wales.

Wales in the thirteenth century was not a unified country under English rule. It was a collection of principalities, some of which acknowledged English overlordship, others of which actively resisted it. The most powerful Welsh ruler was Llywelyn ap Gruffudd, known as Llywelyn the Last, who held the title Prince of Wales.

Edward I became king in 1272. His relationship with Llywelyn was difficult from the start: Llywelyn refused to pay homage to the new king and was increasingly assertive about Welsh independence. In 1277, Edward launched his first military campaign into Wales, forcing Llywelyn to submit. In 1282, a second Welsh revolt broke out. This time, Llywelyn was killed in a skirmish at Builth Wells in December 1282. His brother Dafydd ap Gruffudd continued the revolt but was captured in 1283 and executed — the first person in recorded English history to be hanged, drawn, and quartered.

With the deaths of Llywelyn and Dafydd, Welsh military resistance effectively ended. Edward I was now determined to make that conquest permanent. His instrument was the Statute of Rhuddlan (1284), which imposed English law and administration on Wales — and his physical expression of control was a ring of massive stone castles.

The Iron Ring: Edward's castle-building programme

Beginning in 1277 and accelerating after 1283, Edward I commissioned a network of castles across north Wales designed to encircle and permanently control the region. These castles — at Flint, Rhuddlan, Aberystwyth, Builth, Conwy, Harlech, Beaumaris, and Caernarfon — are known collectively as the Iron Ring.

The Iron Ring was one of the largest and most expensive building programmes in medieval European history. It cost approximately £80,000 over thirty years — a sum equivalent to several times the annual income of the English Crown. It employed thousands of workers from across England and was directed by a single master architect: Master James of St George.

Caernarfon: location, design, and symbolism

Caernarfon Castle was begun in 1283 and took decades to complete. Its location was chosen with care: it sits at the mouth of the River Seiont where it flows into the Menai Strait, the narrow channel of water separating mainland Wales from the island of Anglesey. This position meant the castle could be resupplied by sea even if the surrounding land was held by hostile forces — a critical consideration given Welsh resistance.

But Caernarfon was designed to be far more than a practical fortification. Master James of St George gave it two distinctive features that set it apart from every other castle in the Iron Ring:

Polygonal towers. While most medieval castles used round towers, Caernarfon's towers are multi-angled (polygonal). This distinctive shape was not primarily a military innovation — it was a visual reference. The polygonal towers and the bands of differently coloured stone in the walls were deliberately designed to echo the Walls of Constantinople, the imperial capital of the Byzantine Empire. Edward I had visited the Holy Land on crusade and was deeply aware of the imagery of Roman imperial power. Caernarfon was built to look like the walls of an empire.

The Eagle Tower. The largest tower, known as the Eagle Tower, stands at the western end of the castle. It originally bore stone eagles at its summit — a symbol of Roman imperial authority — and contained the most lavish residential apartments in the castle, intended for the use of the king's representative in Wales.

The birth of Edward of Caernarfon

One of the most important events associated with Caernarfon is the birth of Edward of Caernarfon in April 1284 — the future Edward II. According to a tradition recorded later (though historians debate its origins), Edward I presented his infant son to the Welsh lords as their new Prince of Wales, a native of Wales who could speak no English. Whether or not this story is precisely true, Edward of Caernarfon was formally created Prince of Wales in 1301, establishing a title that has been held by the heir to the English and later British throne ever since.

The birth of Edward of Caernarfon in the castle reinforces its significance not just as a military installation but as a seat of royal authority — a place from which the English Crown would govern Wales.

What does Caernarfon tell us about Edward I's reign?

The use of architecture as political propaganda. Caernarfon was not just a castle — it was a statement. The Roman imperial imagery, the enormous scale, the prominent position commanding the Menai Strait: all of these communicated that English rule over Wales was not temporary but permanent, backed by the full weight of kingly and imperial authority. Edward understood that buildings could govern as effectively as armies.

The role of expert administrators and professionals. The Iron Ring could not have been built without Master James of St George. Edward's willingness to recruit and reward a continental expert reflects the same administrative sophistication we see in his relationship with Robert Burnell — the use of talented professionals, recruited wherever they could be found, to execute royal ambitions.

The permanence of conquest. Unlike the rapid timber castles of the Norman Conquest, Edward's Welsh castles were built in stone from the outset, on a scale intended to last centuries. This tells us that Edward's intention was permanent incorporation of Wales into the English Crown — not just military dominance, but the erasure of the conditions that had made Welsh independence possible.

Return to the question at the start: what do rulers build after conquest? Edward I built Caernarfon — a castle designed to overawe, to remind, and to endure. The polygonal towers still stand today, still projecting the imperial message their designer intended. Seven centuries of Welsh weather have not worn them away.

Revision checklist

Before moving on, make sure you can answer:

1. Why did Edward I begin building castles in Wales, and what events in 1282-1283 made Caernarfon necessary? 2. What is the "Iron Ring" and which castles formed part of it? 3. Who was Master James of St George? Why was he important to Edward I's Welsh campaign? 4. Where is Caernarfon Castle located, and why was this position strategically valuable? 5. What made Caernarfon's design different from other castles of the period? What was the symbolic significance of the polygonal towers and banded stonework? 6. What was the significance of the birth of Edward of Caernarfon in 1284? 7. What does the Statute of Rhuddlan (1284) tell us about how Edward I intended to govern Wales? 8. In what ways does Caernarfon Castle reflect Edward I's understanding of how to use architecture as a political tool?