The castle’s history is intertwined with the de Burgo family, powerful Anglo-Norman lords who sought to control this strategic western port. Richard de Burgo first erected a castle here in 1232, though it barely lasted a year before being destroyed by the Gaelic Irish. Rebuilt shortly after, it met a similar fate in 1247, demonstrating the contested nature of Anglo-Norman expansion in the west of Ireland. The castle continued in use under Richard’s son Walter, who died there in 1271, marking the last documentary reference to this particular fortress.

The excavated remains reveal the eastern corner of what was once a formidable structure. The south-eastern wall, measuring 1.75 metres thick and standing to a height of one metre, was constructed from four courses of roughly hewn migmatite and granite boulders with a clay-bonded core of smaller stones. Its pronounced external base-batter and traces of lime render speak to defensive architecture designed to withstand siege warfare. A substantial buttress, measuring 2.2 by 1 metre, reinforced the north-eastern end of this wall. The north-eastern return wall, built at an oblique angle and lacking the base-batter of its counterpart, shows evidence of later modification, possibly when a lime kiln was constructed against its interior face during the post-medieval period.

The castle appears to have been abandoned around the time Richard de Burgo’s son, known as the ‘Red Earl’, constructed a new high medieval hall nearby. This shift from castle to hall reflects broader changes in Anglo-Norman settlement patterns; as the town became more secure behind newly constructed defensive walls, the need for a strongly fortified castle diminished. Recent excavations in 2017 at Quay Lane have uncovered what appear to be additional remains of this castle complex, suggesting it was more extensive than previously thought. Together with the medieval hall, lime kiln, and smelting works found during the Custom House excavations, these discoveries paint a vivid picture of Galway’s transformation from a contested frontier outpost to a thriving medieval port town.