[4] Wallop survived Pride's Purge to sit in the Rump Parliament and was named by the army grandees as one of the 59 commissioners who sat in judgement at the trial of Charles I.
[5] Under the Commonwealth, Wallop was elected one of the Council of State in 1649 and 1650; however, he submitted to Cromwell's government with very great reluctance, having a determined preference for a republic.
[2] After the fall of the Cromwellian interest, Wallop showed his sincere zeal for the Long Parliament as the support of the republic, and they procured him a seat in 1659 in their council of state.
[2] At the restoration of the monarchy, Wallop was excepted from receiving any benefit of his estate under the Act of Indemnity and subjected to further punishment.
After being required to confess his guilt, he was sentenced to be degraded from his gentility, drawn upon a sledge to and under the gallows at Tyburn with a halter around his neck and to be imprisoned for life.
Henry, through the interest of the then Lord High Treasurer, his maternal uncle Thomas Wriothesley, was permitted to enjoy those estates which his father's treason had forfeited.
The biographer Mark Noble suggests that it was most probable on account of his family connection to Wallop that Thomas Wriothesley was so extremely strenuous in favour of those regicides who had surrendered.