The Rump dissolved
The Rump may have started out as a radical experiment, but the social conservatism of the majority of its members was quickly revealed as it cracked down on radicals in the Army.
In 1649-51, Cromwell won a series of military victories on several fronts against enemies of this new regime - those in Ireland being particularly brutal and bloody and which evoke strong feelings even to this day.
Cromwell expected the Rump to take advantage of these signs of God's Providence (as he saw it) to push through religiously inspired reformist legislation. However, the Rump only showed distrust towards the growing power of the Army and was primarily concerned with legislation ensuring its own survival.
Cromwell finally became so frustrated that on 20 April 1653 he led an armed force into the Commons Chamber (as Charles I had done in January 1642) and forcibly dissolved the Rump, stating: " You have sat too long for any good you have been doing lately ... In the name of God, go!"
The Barebones Parliament
In its place Cromwell established a Nominated Assembly in July 1653, popularly known as Barebones Parliament.
The 144 Members of this Parliament were not elected, but selected by the Army officers for their "godly" religious fervour. This hand-picked group went some way in satisfying Cromwell's wishes, but ultimately it scared the conservative in him and his colleagues with some of its measures for legal and social reform, and for its hostility to the Army.
Lord Protector Cromwell
Early in the morning on 12 December 1653, while the more pious of the Members were at a prayer meeting, a group of Army supporters, led by the general John Lambert, gathered together to vote to dissolve the Parliament.
Lambert had acted because he had already developed another system which he believed would work better than sovereign unicameral government. Lambert put forward his ideas in a written constitution, the Instrument of Government, which instead placed sovereignty in "a single person and a Parliament".
On 16 December 1653 Cromwell, the "single person" intended, was installed as Lord Protector of the realm.