Aberlleiniog Castle

Aberlleiniog Castle was built c.1090 by Hugh of Avranches (Hugh Lupus), the first Norman Earl of Chester, as part of the Norman invasion of Wales under William Rufus. Hugh led a force across the Menai Strait and established this motte-and-bailey castle at Aberlleiniog as a base for Norman control of Anglesey. The Norman occupation of Anglesey was short-lived: in 1098, a Norwegian fleet under Magnus Barefoot arrived in the Menai Strait and allied with the Welsh against the Normans. Hugh of Montgomery, who had accompanied the invasion, was killed by an arrow — according to one tradition, fired by Magnus Barefoot himself. The Normans withdrew from Anglesey and the island returned to Welsh control for nearly two more centuries, until the Edwardian conquest of 1282–1283.

The remains at Aberlleiniog are modest but evocative: a substantial wooded motte (the earthen mound on which the original wooden tower stood) in a quiet woodland setting near the Menai Strait. The motte survives to a good height and can be climbed via the earthworks. There are some fragmentary remains of later masonry (the site may have been reused in the medieval period). The woodland setting adds to the atmosphere of the site. It is not an extensively interpreted site — there are no information panels or facilities — but it is a peaceful and historically significant place that gives a tangible connection to the first Norman attempt to conquer Anglesey, over 900 years ago.

The comparison is instructive: Aberlleiniog (c.1090) and Beaumaris (begun 1295) are separated by two centuries and represent two completely different phases of castle-building. Aberlleiniog is a classic Norman motte-and-bailey — earthwork construction, wooden tower, built rapidly for military control. Beaumaris is a masterpiece of concentric stone castle design, built by Edward I with virtually unlimited resources as the final castle of his ring of fortresses around Gwynedd. Between these two castles lies the entire story of the Norman and Plantagenet engagement with Anglesey. Beaumaris is one of the finest castles in Europe; Aberlleiniog is a quiet earthwork in the woods. Together they tell the complete story of Anglesey under external rule.

For visitors with an interest in medieval history or Norman Wales, Aberlleiniog is worth the short detour — it is free, quiet, and gives a tangible connection to the first Norman attempt to control Anglesey. It is not a site for visitors expecting impressive ruins or interpretation — the remains are earthwork rather than masonry, and the woodland setting means there is little to see beyond the motte itself. But for those who appreciate what a modest earthwork represents (the physical trace of an 11th-century military campaign, of a moment when the future of Anglesey could have gone very differently), it is a rewarding visit. It works well combined with nearby Penmon Priory, Penmon Point, and Beaumaris.

The Norman invasion of Anglesey in 1098 was part of the broader Norman attempt to subjugate all of Wales following the Conquest of England in 1066. Anglesey was strategically important as the granary of Gwynedd — the fertile island that fed the mountainous north Welsh kingdom. Had the Normans succeeded in holding Anglesey in 1098, the subsequent history of north Wales might have been very different. Instead, the Norwegian intervention and the death of Hugh of Montgomery forced a Norman withdrawal, and Anglesey remained under Welsh rule until Edward I's conquest of 1282–1283 — a period of nearly 200 years during which the island was central to the power of the Princes of Gwynedd. Aberlleiniog is therefore a historically significant site: the physical trace of the road not taken in the medieval history of Wales.