The results of detailed pollen-analytical investigations of a core from Lough Dargan, Co. Sligo, Ireland are presented. The pollen diagram spans much of the postglacial and documents changes in woodland composition and cover, and farming activity. Special attention is paid to prehistoric farming and to the significance of cereal-type pollen. The first sign of arable farming coincides with the Elm Decline at c. 3760 BC. This early Neolithic farming phase extended over c. 750 years, the main Landnam phase having a duration of ∼700 years. After a break of about three centuries, Neolithic farming resumed. Late Neolithic farming was at first predominantly pastoral, but later (c. 2360–2130 BC) it had a distinct arable component. In the early Bronze Age, beginning c. 2130 BC, farming increased and woodland was substantially reduced for the first time. From then until the beginning of the late Iron Age (c. 80 BC), there was a sustained and strong human impact. In the late Iron Age, a distinct lull in pastoral farming lasted for about four centuries (c. 80 BC–AD 350). This facilitated woodland regeneration that included yew. Substantial woodland clearance, and farming that included a considerable arable component, characterized the Medieval and later periods. The changes recorded at L. Dargan and other sites in the region are discussed in the light of evidence for climate change provided by regional and super-regional climate proxies. It is argued that climate may not have been a decisive factor in determining human impact and farming activity.