England's eleven years as a republic never found a government that lasted
After Charles I was beheaded in January 1649, England abolished its monarchy and House of Lords and declared itself a Commonwealth. For eleven years it tried parliament after parliament and constitution after constitution, yet no arrangement held for more than a few months, and in 1660 the crown came back as if nothing had happened.
The republic began with a purged parliament. Pride's Purge had expelled every member unwilling to put the King on trial, leaving a Rump that never exceeded two hundred members, under half the original Commons. It was mostly gentry and lawyers, and fewer than a quarter had signed the royal death warrant, so it was a fairly conservative body, reluctant to disturb property or the common law. Traditional elites saw it as an illegal gathering of regicides and upstarts, yet also as the last barrier against open military rule.
Its reforms pleased almost nobody. Court proceedings switched to English from Law French and Latin, and bishops were suppressed while independent congregations were tolerated. At the same time the Rump closed theatres, enforced strict Sundays and banned the celebration of Christmas and Easter, while high taxes to fund the Army angered the gentry. The changes went far enough to irritate the ruling class but not far enough for radicals.
On 20 April 1653 Oliver Cromwell, helped by Thomas Harrison, threw the Rump out for reasons still debated. He tried a nominated assembly, mocked as Barebone's Parliament after one member, the Baptist merchant Praise-God Barebone. Of its 140 members only 25 had sat in parliament before. When its radicals defeated a bill protecting the religious status quo, moderates and conservatives handed power back to Cromwell, and soldiers cleared the rest. A new constitution, the Instrument of Government, made him Lord Protector with powers uncomfortably close to a king's.
Abroad the regime did better. Robert Blake's reformed navy beat the Dutch in the First Anglo-Dutch War, an early step toward English naval dominance, and by 1653 France and Spain recognised the new state. But everything rested on Cromwell's personality and his army grandees. After his death and a brief spell under his son Richard, the system unravelled, and the restored monarchy formally erased the republic's constitutional reforms.
Source: Commonwealth of England