Conwy Castle from the town walls — Wikimedia Commons, CC BY-SA 3.0
Before the Castle: Prehistoric & Early Medieval Conwy
The hill immediately west of Conwy town — known today as Conwy Mountain — carries the remains of Castell Caer Lleion, an Iron Age hillfort whose ditches and ramparts are still clearly visible on the summit plateau. Occupied from around 600 BC, the fort commanded views over the estuary, the coastal plain and the mountain approaches from the south: a strategically significant position that later generations would exploit for the same reasons. The site suggests a substantial settled population in this corner of North Wales well over two thousand years ago.
In the centuries following the Roman withdrawal from Britain, the area formed part of the kingdom of Gwynedd, the most powerful of the early Welsh polities. The rulers of Gwynedd controlled the fertile coastal lowlands and the upland passes into Snowdonia, and the Conwy estuary marked an important boundary between their territories and those of neighbouring kingdoms. Welsh-speaking, Christian and with a sophisticated legal and poetic culture, the kingdom of Gwynedd reached its greatest extent under Llywelyn the Great (1173–1240), who held court at Aberconwy — the monastery at the mouth of the Conwy river, on the site later occupied by the castle — and who was buried there on his death.
Llywelyn ap Gruffudd, his grandson and the last native Prince of Wales to be recognised by the English crown, maintained the independence of Gwynedd through a combination of military skill and political negotiation until the crisis of 1282. His death in a skirmish near Builth Wells that December ended Welsh resistance and opened the way for Edward I’s final and definitive conquest of Gwynedd.
The Edwardian Conquest: Castle & Town
Edward I’s response to the conquest of Gwynedd was a programme of castle building on a scale and of a quality unprecedented in Britain. Between 1283 and the end of the century he constructed four great fortresses — at Conwy, Caernarfon, Harlech and Beaumaris — which together form the most ambitious and best-preserved group of medieval military architecture in Europe. The castles and their associated walled towns were designed not merely as military strongholds but as instruments of colonisation: each was intended to anchor an English borough, populated by settlers from England, in the heart of the conquered Welsh landscape.
Conwy was begun in 1283 under the master builder James of St George, a Savoyard military architect who had already served Edward on campaigns in France and who brought continental European expertise in castle design to North Wales. The castle as it stands today was substantially complete by 1287 — an astonishing achievement involving a workforce estimated at up to 1,500 men at its peak. The town walls, enclosing an area of roughly eight hectares, were built at the same time. The Cistercian monastery of Aberconwy, whose site Edward required for his castle, was relocated upstream to Maenan; its church survives in modified form as Aberconwy House in the town centre, now the oldest house in Conwy and managed by the National Trust.
The walled town was populated initially by English settlers who were granted trading privileges denied to the Welsh population outside the walls — a policy that generated lasting resentment and contributed to the Welsh rising under Owain Glyndŵr in the early 15th century. In 1401 a small group of Glyndŵr’s supporters seized Conwy Castle by a ruse during Holy Week, holding it for several months before negotiating a surrender: one of the few occasions in its history that the castle was taken.
Tudor & Stuart Conwy
The Tudor period brought a degree of reconciliation between Welsh and English political culture, and Conwy’s merchant class grew prosperous on trade through the estuary. The finest monument to this prosperity is Plas Mawr, the Elizabethan town house built by Robert Wynn between 1576 and 1585. Wynn was a Welsh gentleman who had travelled widely in Europe and brought continental taste back to Conwy: his house, with its elaborate plasterwork, decorated gables and compact courtyard plan, is the finest surviving example of Elizabethan domestic architecture in Wales and one of the best in Britain.
The Civil War brought Conwy Castle briefly back into military use. It was held for the king, garrisoned and besieged, before falling to Parliamentary forces in 1646. After the Restoration the castle was no longer maintained as a military installation and entered the long decline that characterised most medieval fortresses in the post-gunpowder era. By the 18th century it was a picturesque ruin, admired by painters and poets on the Grand Tour of Wales.
The Victorian Age: Bridges, Railway & Tourism
The 19th century transformed Conwy and its region more rapidly than any period since the Edwardian conquest. Thomas Telford’s suspension bridge, completed in 1826 as part of the Holyhead road improvement programme, was the first fixed crossing of the Conwy estuary and ended the reliance on ferries that had constrained movement here for centuries. Telford designed the bridge towers in a deliberately Gothic style to complement the castle: the first explicit acknowledgement that the town’s medieval architecture was an asset to be respected rather than merely tolerated.
Robert Stephenson’s tubular rail bridge, completed in 1848 alongside Telford’s structure, brought the Chester–Holyhead railway across the estuary and opened the entire North Wales coast to tourism. The effect on the region was dramatic: within a generation, Llandudno had been transformed from a small copper-mining settlement into one of the most fashionable seaside resorts in Britain, drawing visitors from Liverpool, Manchester and the industrial towns of the north-west. Conwy itself benefited from the tourist trade; the castle, by now in State care, attracted a growing stream of visitors for whom a medieval fortress was an appropriate object of curiosity and admiration.
The railway also accelerated the slate industry in the Conwy Valley and beyond. Quarries at Betws-y-Coed, Trefriw and Llanrwst expanded to meet the demand for roofing slate from the rapidly growing cities of England, and the valley became an industrial as well as an agricultural landscape. Much of that industry has now gone, but its legacy is visible in the quarry scars, the chapel-dense villages and the distinctive terraced housing of the valley towns.
The 20th Century & World Heritage Status
Conwy entered the 20th century as a modest market and tourist town, its population never having grown to match the ambitions of its medieval founders. The castle and walls passed into State guardianship and were progressively consolidated and opened to the public. The town within the walls retained — and largely retains today — an unusually complete stock of historic buildings, partly because the relative absence of economic development pressure meant there was little incentive to demolish and rebuild.
The A55 expressway, bored through the Conwy Tunnel beneath the estuary in 1991, removed the bottleneck that had previously funnelled all coastal road traffic through the narrow streets of the walled town. This was transformative for the town’s character: relieved of through traffic, the historic centre became quieter, more pedestrian-friendly and more attractive to visitors.
In 1986 Conwy Castle and town walls were inscribed as a UNESCO World Heritage Site as part of the ‘Castles and Town Walls of King Edward in Gwynedd’, a designation shared with Beaumaris, Caernarfon and Harlech. The inscription recognised the exceptional quality of this group of monuments as a unified expression of medieval military architecture and Edwardian colonial strategy. Today Conwy is one of the most visited historic towns in Wales, drawing visitors from across Europe and beyond who come for the castle, the walls, the quayside and the concentrated sense of a medieval town that has survived largely intact into the 21st century.
Explore Conwy