Written by archaeologist and historian in residence Barry Lacey


Ferns, the location of St Aidan’s monastery, is synonymous with the later medieval period and its association with Diarmait Mac Murchada, king of Leinster (d. 1171 AD), who established Ferns as his royal caput, and later infamously invited an Anglo-Norman mercenary force to Ireland.

The importance of later medieval Ferns is reflected in its surviving built heritage, which includes St Edan’s Cathedral, the remains of a thirteenth-century cathedral, the twelfth-century Augustinian foundation of St Mary’s Abbey and the impressive thirteenth-century Marshal castle located near the western limits of the town.

Perhaps unsurprisingly, it is the later medieval period that emerges most clearly from the results of modern archaeological investigations in the Ferns area, which includes about sixteen excavations in the vicinity of the castle alone.

The known archaeology excavations in Ferns on the map

Map of Ferns featuring all archaeological excavations undertaken to date. Note a square indicates an excavation of the possible early medieval enclosures. Image courtesy of Michael ‘Bodhi’ Rodgers.

In total c. 44 excavations have been undertaken at various locations around the town (although 23 of these have been deemed of no-archaeological significance) and whilst these excavations have focused on the later medieval period, Ferns early medieval heritage is also becoming increasingly apparent.

To date six archaeological digs have been undertaken on ditches that may relate to the early medieval monastic boundary of St Aidan’s monastery, which was founded in c. 598 AD. These ‘monastic excavations’ have been complemented by extensive recent geophysical surveys (most recently in 2021) which have specifically targeted the route of the early medieval monastery.

Prior to these excavations and surveys the archaeological evidence for St Aidan’s monastery at Ferns was modest, but included high crosses and cross slabs fragments. Whilst the archaeological evidence was subtle, the life of St Aidan was well documented historically and there was also further occasional historical references to his monastery in Ferns, such as Viking raids of St Aidan’s monastery in 835 and 839 AD.

Despite clear historical accounts of St Aidan, the limits, position, scale and form of his monastic foundation remained comparatively poorly understood.

However, in the last five years three excavations and one programme of geophysical survey have added crucial new data on Ferns early medieval enclosure(s) shedding further light on the possible complexities of this monument(s).

Aerial view of planned geophysics and st Aidan's Monastery

Map of Ferns showing the completed (solid line) and planned (dotted line) geophysical areas in 2021 (together with the outline of the survey from 2015. The geophysical survey in 2015 was conducted as part of the ‘Monastic Ireland: landscape, community and settlement’ project: see also Bhreathnach and Dowling 2021). Image courtesy of Micheal ‘Bodhi’ Rodgers.

Previously, two main circuits were suggested for the monastic boundary at Ferns, firstly by Doyle (2016), who proposed an inner enclosure c.200m in diameter and an outer enclosure c.300–350m in diameter.

Then latterly by McLoughlin (McLoughlin 2020; McLoughlin and Stafford 2020) who postulated a much larger monastic site, with an outer diameter of over 500m. Both these putative circuits have merit, each supported by clear archaeological evidence.

However, since these circuits were proposed an extensive programme of magnetic gradiometry was undertaken throughout Ferns in 2021 (across six areas in the town totalling 10 hectares).

These surveys were undertaken by Dr Ger Dowling on behalf of the University of Colorado Denver, in collaboration with the IAFS and local archaeologist Barry Lacey.

The surveys identified an impressive array of sub-surface features, many of which are of clear archaeological significance and seemingly relate to occupation and agriculture spanning several centuries or even millennia.

Of particular interest was the identification of possible segments of the northern circuit of the early monastic boundary.

Based on the 2021 survey results and other evidence – notably the identification of a cropmark on Google Earth Pro to the northwest of the town and the continuing IAFS excavations around St Marys Abbey (see blog four of this series) – alternative layouts for the early medieval enclosure(s) at Ferns may now also be proposed.

It is increasingly probable that the enclosures are more complex than originally anticipated, with the possibility that the monastery had either additional outer enclosing circuits, and/or an annex to the outer enclosure, which, based on the new survey results, is more likely to be similar in shape to the smaller circuit originally proposed by Doyle (2016).

Whatever the correct interpretation is with regard to Ferns inner, outer, outermost or annex enclosures, what is certain is that the site is more complex than previously presented and is also likely to be multi-period in date, having continued to grow as a monastic (or ecclesiastical) site from at least the sixth to the tenth century and beyond.

The scale, form and antiquity of this enigmatic enclosure will be explored in much more detail in a chapter in the upcoming Discovering Medieval Ferns volume.

Further Reading for St Aidan’s Monastery

Bhreathnach, E. and Dowling, G. 2021 ‘Forming an episcopal see and an Augustinian foundation in medieval Ireland: the case of Ferns, Co. Wexford’, Proceedings of the Royal Irish Academy 121C, 191–226.

Doyle, I. 2016 ‘Telling the Dancer from the Dance: The Archaeology of Early Medieval Wexford’. In Doyle, I. and Browne, B. (eds). Medieval Wexford: Essays in Memory of Billy Colfer, 35–61. Dublin.

McLoughlin, C. 2020 ‘From Early to Late: uncovering medieval Ferns’, Archaeology Ireland. vol. 34, No. 2, issue 132, 30–4.

McLoughlin, C. and Stafford, E. 2020 ‘Medieval Ferns: from monastic centre to medieval town’ in Corlett, C. and Potterton, M. (eds) The Town in Medieval Ireland in the light of recent archaeological excavations, 85–100. Dublin.

Acknowledgment of Support

This blog is number six of a ten-part series entitled ‘Discovering Medieval Ferns’ which has been funded by the ‘Rediscovering Ancient Connections – The Saints (Ancient Connections)’ Project.

Ancient Connections Logo for Discovering Medieval Ferns blog series

Ancient Connections’ is an ‘inter-reg’ cross-border arts and heritage project linking Pembrokeshire and north Wexford, which strives to revive the ancient links between these communities, allowing them to rediscover their shared heritage and trade knowledge, experience, and skills.

‘Ancient Connections’ have also funded a major academic volume, also entitled ‘Discovering Medieval Ferns, upon which this blog series is based.

Discovering Medieval Ferns Book Cover 2023

This volume, which includes fifteen papers from an interdisciplinary team of twenty+ scholars, aims to highlight the remarkable history and archaeology of medieval Ferns, focusing on intriguing discoveries from recent excavations and research programmes.

The volume, which is the most complete picture to date of the origins and evolution of medieval Ferns, will be published by Four Courts Press later in 2023.

The logos of EU and Welsh bodies involved with Ancient Connections that have supported the excavation at St Mary's