Instrument of Government

The Instrument of Government was the first constitution of the Commonwealth of England, Scotland and Ireland and was also the first codified and written constitution in England. It was drafted by Major-General John Lambert in 1653.

The work incorporates elements from the document Heads of Proposals (1647), which contained the constitutional proposals offered by Army Council to Charles I of England. Under the new constitution, the executive power was held by the Lord Protector. Each Lord Protector was intended to hold the office for life, with no term limits. The legislative power was held exclusively by the then-unicameral Parliament of England, and each session of Parliament had to last for at least five months. An English Council of State would replace the Privy Council, and the actions taken by the Lord Protector would require the consent of a majority of the council to be legal. A number of limits were placed on the authority of the Lord Protector to prevent him from acting as an absolute ruler. The constitution authorised the maintenance of a standing army, which would include 10,000 soldiers as its cavalry, and 20,000 soldiers as its infantry. The document authorised the maintenance of a separate navy, but did not define the intended size of its forces.

The Instrument of Government was adopted by the Council of Officers on 15 December 1653 and Oliver Cromwell was installed as the first Lord Protector on the following day. In January 1655, Cromwell dissolved the Parliament and started ruling without constitutional limits, in a period of military dictatorship by the Major Generals. The Instrument of Government was replaced in May 1657 by England's second codified constitution, the Humble Petition and Advice.