High-treason synonyms

On the 24th of November he was indicted for high treason at the Old Bailey, the chief ground being a paper of association for the defence of the Protestant religion, which, though among his papers, was not in his handwriting; but the grand jury ignored the bill.

To maintain or affirm the right of any person to the crown, contrary to the provisions of the act, is high treason by an act of 1707.

You're talking about high treason at the VP level at least to access those things.

They were pronounced by the Council of Blood to be guilty of high treason (June 2, 1568).

On the 19th of January 1648 Cromwell was accused of high treason by Lilburne.