Hugh De Lacy, one of the Normans who came to Ireland after Strongbow, built the original fort circa 1172, having been granted the Kingdom of Meath by Henry II. Later a stone castle was built on the site. This castle formed part of the defences of the town during the siege of Drogheda during the Cromwellian conquest of Ireland in 1649. The fort's English defenders attempted to surrender to Parliamentarian troops under Oliver Cromwell but were massacred when they gave themselves up on 11 September 1649.