<P> On January 4, 1649 the Rump Parliament declared "that the people are, under God, the original of all just power; that the Commons of England, being chosen by and representing the people, have the supreme power in this nation". </P> <P> The Instrument of Government was adopted by Parliament on December 15, 1653 and Oliver Cromwell was installed as Lord Protector on the following day . The constitution set up a state council consisting of 21 members while executive authority was vested in the office of "Lord Protector of the Commonwealth"; this position was designated as a non-hereditary life appointment . It also required the calling of triennial Parliaments, with each sitting for at least five months . </P> <P> The Instrument of Government was replaced in May 1657 by England's second, and last, codified constitution, the Humble Petition and Advice, proposed by Sir Christopher Packe . The Petition offered hereditary monarchy to Oliver Cromwell, asserted Parliament's control over issuing new taxation, provided an independent council to advise the king and safeguarded' Triennial' meetings of Parliament . A modified version of the Humble Petition with the clause on kingship removed was ratified on 25 May . This finally met its demise in conjunction with the death of Cromwell and the Restoration of the monarchy . </P> <P> Other examples of European constitutions of this era were the Corsican Constitution of 1755 and the Swedish Constitution of 1772 . </P>

What is constitution and what is its importance