To inform the consideration of The Inventory of Historic Battlefields in Wales, a phased programme of investigation was undertaken on the 1648 battle of St Fagans. Detailed reports of these investigations are available and comprise documentary and historical research (Border Archaeology), and non-invasive and invasive fieldwork (Archaeology Wales 2012 and 2013).

The Battle of St Fagan's can be viewed against the backdrop of the Welsh Rising during the Second English Civil War and was the last set-piece defeat for the Royalist forces; it effectively signalled the end of any realistic Royalist attempts to reinstate the full authority of Charles I. Prior to the battle, the Royalist intent, under the command of Major-General Laugharne, was to march to and seize Cardiff, however a small Parliamentary force of approximately 3000 men under Colonel Thomas Horton, which had been engaged in an arduous campaign in and around Brecon, marched south in order to stop them, reaching St Fagan's on 4 May 1648. Here Horton set up temporary headquarters, awaiting reinforcements from Cromwell, in a farmhouse called Pentrebane (ST 1202 7852, Grade II Listed Building No. 82247). The Royalists at this point were just two miles away and initially set up camp on the Downs around St Nicholas (ST 091 742) before retreating westward into the Vale of Glamorgan, returning to St Nicholas on 7 May.

It is difficult to discern the exact narrative of events of the engagement itself. Several correspondence accounts exist from the Parliamentarian side but there is a lack of contemporary Royalist sources.

The Royalists mounted an attack around 7am on Monday 8th May, hoping to gain victory before the arrival of Cromwell's reinforcements. However they were soon out manoeuvred and out flanked by the Parliamentarians, within 2 hours the Royalist army was almost completely encircled by the Parliamentarians at which point they broke and ran. The Parliamentary cavalry then rounded up prisoners and of the 8000 Royalist men estimated to have begun the battle, about 3000 ordinary soldiers and upwards of 400 officers were taken prisoner, including Laugharne. In addition to this, over 2000 firearms as well as other weapons were taken.

The exact location of the battle is not certain; it is not mentioned explicitly by any of the primary sources and is likely to have spread over a relatively large area and one that grew larger once the Royalist forces had scattered in retreat. Historic and modern Ordnance Survey mapping give the site of the battle next to Tregochas at ST 1066 7798. It seems clear that both armies deployed on either side of a stream or river and it is with a degree of confidence that this stream is identified as the Nant Dowlais where the existing bridge across the river at ST 10437 77909 occupies the same location as the bridge contested in the battle. In support of this assumption, a programme of archaeological investigation, including metal detector survey in fields directly to the north, east and south of the bridge revealed a large assemblage of finds relating to the battle including lead shot, buckles, buttons and cavalry equipment as well as personal items such as spoons, a plate and thimbles (Archaeology Wales 2012). Further archaeological investigations between 500m and 1.3km away from the bridge also produced finds, though to a much lesser extent suggesting they may be further from the main area of the battle or subject to less intensive fighting (Archaeology Wales, 2013).

Other locations are also traditionally associated with the battle, including a field to the rear of the present rectory house in St Fagan's (ST 1214 7736), marked on the 1839 tithe apportionment as `Cae Meirch? (Field of the Horse/War-horses) where Colonel Horton supposedly gathered all his horses in preparation for the battle. There is also mention of a tumulus investigated by the local antiquarian W. David in 1872 to the north-east of St y Nyll where evidence of human remains was identified, suggested as possibly representing the burial of certain individuals killed during the battle. It is unclear whether the tumulus investigated by David is identifiable with the barrow mound investigated by Savory in 1958 at ST 1008 7829 (Scheduled Monument GM204).

RCAHMW (Battlefields Inventory), Jan 2017

Bibliography
Archaeology Wales, 1648 Battle of St Fagans, Cardiff: Battlefield Survey (2012).
Archaeology Wales, 1648 Battle of St Fagans, Cardiff: Battlefield Survey (2013).
Border Archaeology, St Fagans (8 May 1648): Documentary and Historical Research Report (2009).