This period includes some of the most turbulent events in the whole course of British history: the civil wars, the trial and execution of King Charles I and the interregnum regimes of 1640-1660. The Short Parliament of 1640, the Long Parliament and `Rump’ (1640-53, 1659-60), the Nominated or 'Barebones' Parliament of 1653, and the three Cromwellian Parliaments of 1654, 1656-8 and 1659 were all difficult assemblies: the very legitimacy of some of them was contested. It was an exceptional period in parliamentary history, and it took place in the context of a rapidly-developing print culture, with the arrival of weekly newspapers bringing unprecedented and partisan commentary on proceedings and personalities. There were republican experiments; the Long Parliament was for a time not only a legislative assembly but also provided executive government; Members of the Nominated Assembly of 1653 were not elected at all, but were appointed under the patronage of Oliver Cromwell. These were also constitutionally innovative times for the union between the then nations of Britain. In 1653, MPs sat in an English Parliament for Scotland and Ireland, albeit as government nominees, and Irish and Scots constituencies returned MPs to Westminster in the Parliaments of 1654, 1656 and 1659.

Some 1807 Members of Parliament are known to have been authorised to sit during the period, in 316 constituencies. Because of the importance of executive authority vested in Parliament at this time, we will include articles on executive committees of the Long Parliament.  These will include the Committee of Safety, a body which took crucial political decisions, and its successor, the Committee of Both Kingdoms, which came into being after the alliance made between the English Parliament and the Scots Covenanters.

The introductory survey will include the elements usual in History of Parliament volumes, dissecting MPs’ backgrounds, education, social networks, business interests, wealth and religious views.  It must also incorporate a substantial analysis of high politics of the time, when Parliament was subject to the prototype ‘party’ groupings of Independents and Presbyterians, ‘Country’ members and ‘Kinglings’, to name a few of the often pejorative, always contentious, labels of the day.

Among the household names to figure among our biographies will be not only Cromwell, but men like John Pym, John Hampden, Sir Henry Vane junior, Denzil Holles, Col. Thomas Harrison and the libertine republican, Henry Marten. Usually better-known in other spheres, but given a new dimension here, are MPs like the jurist and scholar John Selden, the poet Andrew Marvell, and the civil servant and spymaster John Thurloe.  The extraordinary circumstances of the 1650s, in particular, mean that there are also MPs drawn from hitherto under-represented ranks of society, who had made their way into public life from relatively humble backgrounds through such means as the army, the navy and government, and who sometimes brought socially or religiously radical perspectives to the Commons.  Alongside them are some English peers who had previously sat in the Lords, abolished in 1649.

By January 2018 we passed the half-way point in revising draft biographies of MPs and constituency articles, incorporating modifications indicated by research over the section as a whole, and new information revealed by digitised resources. The intended publication date of this Section is around 2020.