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Choose a route into Ireland’s past: follow the newest additions, find a particular year or subject, or browse every available period.
Welcome to Emerald Archives
Emerald Archives presents Ireland’s story one reference year at a time, from the deep prehistoric past to the modern era. Each article explores the evidence, people, places and developments associated with a particular year and places them within their wider historical setting. The collection brings together archaeology, politics, society, religion, culture, conflict, everyday life and changing landscapes in one continuously expanding timeline. New articles appear here as the archive grows. You can also explore the full Irish History Timeline, search the archive directly, or use Explore to move through the collection by period and subject.
Start Exploring
Choose a route into Ireland’s past: follow the newest additions, find a particular year or subject, or browse every available period.
30270–30261 BCE
Derryvree’s Sedge Basin
Modern BCE notation can misleadingly suggest a precision equivalent to a historical year. It has none here. Radiocarbon laboratories conventionally express age in years “BP”, where present means AD 1950; a radiocarbon age must then be calibrated because the amount of atmospheric carbon-14 has varied over time. The internationally maintained IntCal20 curve extends that calibration framework to 55,000 calendar years BP, but uncertainty becomes substantial at this antiquity. A result may therefore indicate a broad span of centuries or millennia rather than one precise year.
Derryvree’s Bogbean and Milfoil
At this depth in time, calendar precision is impossible. The closest major environmental record is at Derryvree, near Maguiresbridge in County Fermanagh. Roadworks there in 1969 cut through a drumlin and revealed freshwater silts and fine sands, rich in organic matter, trapped between two separate sheets of glacial till. The sequence provides a secure relative history: ice had first crossed the locality; an ice-free or ice-marginal interval then allowed a wetland to form; and ice later returned, burying the deposits beneath fresh till.
Derryvree’s Tundra Herbarium
The closest Irish evidence comes from Derryvree, near Maguiresbridge in County Fermanagh. Roadworks in 1969 cut through a drumlin and revealed a remarkable sequence: a freshwater bed of silts and fine sands lay between two thick deposits of glacial till. The lower till recorded an earlier passage of glacier ice. Then, for a time, freshwater sediments and organic material accumulated. Later glacial action buried and preserved the deposit beneath an upper till. The discovery offered an unusually clear reminder that glaciation was not one uninterrupted frozen state, but a sequence of advances, pauses, altered drainage and renewed ice growth.
