The cafe and station of the Welsh Highland Railway at Caernarfon. You can see Caernarfon Castle in the background

---

A history of Caernarfon and its Castle

Caernarfon is one of the most historically layered towns in Wales — a place where Roman military power, medieval Welsh princes, and Edward I’s imperial ambitions all left deep marks. Its castle is among the most architecturally distinctive in Europe, and both town and fortress form a single, planned medieval complex that still shapes Caernarfon’s street pattern today.

Below is a full, structured account of the town’s history, the castle’s development, and their shared significance, grounded in authoritative sources.

---

The Town of Caernarfon: A Historical Overview

Roman Origins: Segontium

• The earliest major settlement was the Roman fort of Segontium, founded around AD 75 on a low hill southeast of the modern town.

• It guarded the Menai Strait and controlled local tribes; after the Roman withdrawal (c. 380–390), it remained a seat of local chieftains.

• The Welsh name Caer yn Arfon (“the stronghold opposite Môn/Anglesey”) derives from this Roman presence.

Early Medieval & Norman Period

• A Celtic church was founded here in the 5th century, showing continuity of settlement.

• The Normans briefly penetrated the region in the late 11th century, building a motte-and-bailey castle around 1088, but the Welsh soon recaptured it.

Welsh Princes of Gwynedd

• For over a century, Caernarfon was in Welsh hands, forming part of the power base of the princes of Gwynedd.

• Medieval Welsh tradition linked the site with Constantine the Great and the legendary Dream of Macsen Wledig, emphasising its symbolic importance.

Edward I’s New Town (1283–1284)

After conquering Wales in 1282–83, Edward I transformed Caernarfon:

• He built a new walled town beside the castle, laid out on a grid pattern, and granted it a borough charter in 1284.

• English settlers were invited to populate the new borough, making it the administrative capital of North Wales.

• The town walls, still exceptionally well preserved, were built simultaneously with the castle.

Harbour & Later Development

• Caernarfon’s harbour became important in the 19th century, especially for exporting slate from nearby quarries.

• The town expanded far beyond its medieval walls but retains its historic core and remains the administrative centre of Gwynedd.

---

Caernarfon Castle: Architecture, Purpose & History

🧱 Origins and Construction

• The first fortification on the site was the late 11th‑century motte-and-bailey castle.

• Edward I began replacing it with the present stone fortress in 1283, as part of his “iron ring” of castles to control Wales.

• The castle and town were intended as a combined administrative and military centre — a deliberate symbol of English rule.

Architectural Distinctiveness

• The design evokes the walls of Constantinople, with polygonal towers and banded masonry — a conscious imperial reference.

• The chief architect was Master James of St George, one of medieval Europe’s greatest military engineers.

• Although the exterior looks complete, many interior buildings were never finished.

Cost and Scale

• Construction from 1283 to 1330 cost between £20,000 and £25,000, an enormous sum for the period.

Conflict and Siege

• 1294: The town and castle were sacked by Madog ap Llywelyn during a Welsh rebellion; the English retook them in 1295.

• 1400–1415: The castle was besieged during the Glyndŵr Rising but held out.

• English Civil War: Held by Royalists and besieged three times — the last time the castle saw active military use.

Decline and Restoration

• After the Tudor accession in 1485, tensions eased and the castle fell into disrepair.

• Major restoration began in the 19th century, funded by the state.

Royal Ceremonies

• 1911: Investiture of the Prince of Wales (future Edward VIII).

• 1969: Investiture of Prince Charles (now King Charles III).

• These ceremonies revived the castle’s symbolic role.

UNESCO World Heritage Status

• In 1986, Caernarfon Castle and its town walls were inscribed as part of the “Castles and Town Walls of King Edward in Gwynedd” World Heritage Site.

---

Why Caernarfon Matters

Caernarfon is unique because:

• It preserves a complete medieval urban plan alongside its castle.

• Its architecture expresses imperial symbolism rarely seen in Britain.

• It embodies the long, often contested relationship between Wales and England.

• It remains a living town whose medieval walls still define its centre.

---