The Triennial Act

Also called the Dissolution Act, this was passed by the English Long Parliament during the reign of King Charles I. It required Parliament to meet for at least a fifty-day session once every three years, with the intention to prevent the Monarch from ruling without Parliament, which had already happened between 1629 and 1640.

If the King failed to call Parliament, the Act required the Lord Chancellor to issue the writs, and if there was no response, the House of Lords could assemble and issue writs for the election of the House of Commons. What makes the Act unusual, is Clause 11, which stated that the bill would receive the royal assent before the end of the parliamentary session.