This period includes some of the most turbulent events in the whole course of British history: the Civil War, 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. 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, Sir Henry Vane junior, Denzell Holles, Col. Thomas Harrison and the libertine republican, Henry Marten.

At November 2012, the biographies of all but a handful of MPs, and most constituency articles, have been completed in draft. The intended publication date of this Section is 2016.