French and a lawyer named Nicholas Plunkett then assumed control of the Supreme Council and tried to promote a better peace treaty with the Royalists at the same time as a more vigorous prosecution of the war in Ireland. A new Treaty was signed with the Royalists in 1648 and French was prominent in trying to secure the widest possible support within the Confederation for it. However, the most hardline Catholic elements remained hostile to it. In any event, the Royalist/Confederate alliance lasted little more than a year -as they were crushed by an English Parliamentarian conquest of Ireland which began in 1649. The Parliamentarians were extremely hostile to Catholic clergy, executing them when they apprehended them, and French deemed it prudent to leave Ireland in 1651, and the remainder of his life was passed on the continent of Europe.