In 1648 intervention was preceded by a series of key votes in the House and trenchant declarations from the army which were not readily reconcilable, and a confrontation of some sort looked likely. It was not the first time that the army had intervened to alter the balance of power in Parliament: in August 1647 it had facilitated by its very presence in London the overturning of a coup by the Presbyterian party. ‘Pride’s Purge’ did not come out of the blue. On the whole, the exercise was conducted with courtesy, but none the less, 45 MPs were arrested and four times as many were turned away or, intimidated by the military force, did not even attempt to gain access.

Armed with a list of the offending Members compiled the previous night, the troops’ commanding officer, Colonel Thomas Pride, stood with Thomas Grey, Lord Grey of Groby, on the stairs to the House and – having identified them individually – excluded those who tried to enter, or let them through, according to that list. Soldiers from the New Model army, which in its council of officers embodied the most potent collective voice opposing the treaty and which among its ranks included some of the most radical spokesmen for the ‘will of the people’, arrived at Westminster and proceeded to purge the House of Commons of those MPs who had supported a deal with the king.

On 6 December 1648, three weeks after Parliament had taken a critical step towards a peace treaty with Charles I that would finally end civil war, events took a dramatic turn. Yet while there are no mathematically exact historical parallels, work at the History of Parliament reveals many resonances with past political crises, and some where the stakes have been at least as high and the consequences arguably even more far-reaching. From day to day the balance has seemed to shift between rejection and acceptance of the proposed ‘divorce settlement’ with the EU, and between groups with radically different visions of the best way forward for a country where opinion is sharply divided. Over the three weeks since the prime minister announced her Brexit deal, observers might have been forgiven for detecting unprecedented twists and turns in politics at Westminster. Dr Vivienne Larminie of the House of Commons 1640-1660 section moves on from 15 November to 6 December 1648, to look at a critical vote and a forcible change of direction…

As MPs prepare to vote over whether or not to accept the Brexit deal negotiated by Theresa May, we have the second post in the series on the tumultuous events of 1648-1649, as parliamentarians disputed with each other over a treaty which might end the civil wars.

Pride's Purge by David Underdown