300 Pollen data

The Irish Iron Age began around 500 BC and continued until the Christian era in Ireland, which brought some written records and therefore the end of prehistoric Ireland. The late Iron Age saw sizeable changes in human activity. Pollen data extracted from Irish bogs indicates that "the impact of human activity upon the flora around the bogs from which the pollen came was less between c. 200 BC and c. 300 AD than either before or after." The third and fourth centuries saw a rapid recovery. The reasons for the decline and recovery are uncertain, but it has been suggested that recovery may be linked to the purported "Golden Age" of Roman Britain in the third and fourth centuries. The archaeological evidence for trade with, or raids on, Roman Britain is strongest in northern Leinster, centred on modern County Dublin, followed by the coast of County Antrim.