The siege of Drogheda or the Drogheda massacre took place 3–11 September 1649, at the outset of the Cromwellian conquest of Ireland. The coastal town of Drogheda was held by the Irish Catholic Confederation and English Royalists under the command of Sir Arthur Aston when it was besieged by Parliamentarian forces under Oliver Cromwell. After Aston rejected an invitation to surrender, the town was stormed and much of the garrison was executed including an unknown but "significant number" of civilians. The outcome of the siege and the extent to which civilians were targeted is a significant topic of debate among historians.