 Limerick was one of the last fortified cities held by an alliance of Irish Confederate Catholics and Royalists against the forces of the English Parliament.Its garrison, led by Hugh Dubh O'Neill, surrendered to Henry Ireton after a protracted and bitter siege.Over 2,000 soldiers of Cromwell's New Model Army were killed at Limerick, and Henry Ireton, Cromwell's son-in-law, died of plague.