The core‐periphery frame of analysis gives useful insights into Anglo‐Irish relations during the four centuries of the rise and decline of the British empire. The emigration from the Irish periphery of almost half those surviving to maturity has been the dominant feature of the relationship for 135 years. Emigration on this scale has created in southern Ireland a political void within which the institutional framework has petrified, leaving it ill‐fitted to cope with the situation created by the ending of empire. With Britain itself now peripheralised, massive emigration from Ireland is no longer possible, and a population that declined for over a century is now growing more rapidly than that of any other European country. Numbers at work, meanwhile, continue their 135 year‐old decline. The failure of half the population to get a livelihood in the Irish periphery underlies catholic/protestant strife in the north.