Testing Ringfort Chronology in Western Ireland through a Multi-Sited Study Using Geophysical Survey, Targeted Soil Coring, and Radiocarbon Dating

Abstract

This dissertation reopens the chronology of the Irish ringfort. Roughly 45,000 of these earthen and stone enclosures survive across the island, which are conventionally dated to a window in the Early Middle Ages (600–1000 AD) and are broadly understood as the quintessential dispersed agricultural settlement of that era. However, the tight association between the site type and the time period has been shaped as much by the historical context of archaeology in Ireland as by actual material evidence. To test ringfort chronology, this project developed and applied a methodology called para-excavation, which combines field survey, magnetometry, ground-penetrating radar, and targeted soil coring to recover stratigraphically controlled radiocarbon samples from many sites in a single region without full excavation. Through the Geophysical Ringfort Archaeological Survey Project (GRASP), para-excavation was applied to nine ringforts in and around the civil parish of Ballintober, Co. Roscommon, between 2023 and 2025. The study yielded 47 radiocarbon dates from eight sites, centering on a time span from the early fourth century BC to the late seventeenth century AD. The results confirm an early medieval floruit, but place the regional peak at 800–850 AD, roughly 150 years later than the island-wide peak. Four sites produced Iron Age dates, including five determinations from stratified contexts at Rath Maol (RO034-006). A regional gap in activity from approximately 50–250 AD aligns with the `Late Iron Age Lull' observed widely across Ireland. At the other end, four sites yielded post-1000 AD activity, much of it from the types of shallow or disturbed contexts most vulnerable to taphonomic destruction and analytical exclusion; the seeming sharpness of ringfort decline after the turn of the millennium might be partly an artifact of site formation processes in the past or sampling strategies in the present. Taken together, the GRASP sites demonstrate consistent human engagement with the same locations across more than two millennia, spanning periods that conventional chronology treats as fundamentally separate. Periodization is a necessary tool for archaeology, but recent advances in absolute dating now make it possible to build chronologies from the ground up, site by site and region by region, rather than fitting new evidence into inherited frameworks. Like many other Irish site types, ringforts are best understood as persistent places: locations whose stories extend far beyond the construction of the standing monument, and which reward close regional study, attentive to the full range and complexity of their evidence.