The English invasion of Ireland is of central importance to the interconnected histories of Britain and Ireland. Yet there is still disagreement over the agency of its ultimate sponsor, King Henry II. This article argues that from the very beginning of his reign as king of England, Henry utilised a rising tide of intolerance among Europe’s clerical elite for those holding non-standard beliefs and customs to secure reluctant papal approval for an invasion of Ireland. Once that invasion finally got underway a decade and a half later, members of his court portrayed Henry’s firm rule as the necessary precursor to the reform of Irish religion and culture. This propaganda sought its justification in the intellectual and cultural flourishing of the twelfth-century renaissance, which provided European commentators with newly-revived models of logic and classification. In was also carried out amidst Crusade-inspired justifications for the violent subjugation or killing of religious non-conformists. The essential point, however, is that these clerical descriptions did not necessarily reflect contemporary secular opinion. When works written for secular audiences in the vernacular are analysed, they present a much more nuanced image of Ireland and the Irish. Gone are the references to civilising or reforming missions, and the clear sense of cultural superiority. What remains, however, is the fundamental belief that strong, centralised order is required for the successful running of society. This is what the English invaders told themselves, and this is what informed the first generation of settlement in Angevin Ireland.