On 15 August, Oliver Cromwell arrived with an expeditionary force of 12,000 to begin the conquest of Ireland, and Venables took part in the storming of Drogheda. Along with Michael Jones' brother Sir Theophilus, a detachment led by Venables joined forces with Sir Charles Coote in Ulster. Over the next twelve months, the three conducted a campaign to subdue the north, including the battles of Lisnagarvey and Scariffhollis. Charlemont, the last Confederate stronghold in Ulster, surrendered in August 1650, and their only significant field army dissolved in December when the Marquess of Clanricarde went into exile.