The Parliamentarians accused him of high treason, and his estates were confiscated by the English Commonwealth's Act for the Settlement of Ireland on 12 August 1652 and Beaulieu was given to Sir Henry Tichborne as tenant to the state by Cromwell. Fingall's son and heir by 1677 had recovered much of the family property, but Beaulieu was permanently lost to the Plunketts.
He was accused of high treason by Parliamentarians, and his properties were seized by the English Commonwealth's Act for Ireland in 1652. Cromwell granted Beaulieu to Sir Henry Tichborne as a state estate. By 1677, Fingall's son had recovered much of the family land, but Beaulieu was permanently taken over by the Plunketts.