The eleven years between the wintry, symbol-laden death of Charles I in January 1649 and the triumphalist return of Charles II in May 1660 make up the most perplexing period in English history – a bewildering game of unintended consequences, compromises and missed opportunities. The Interregnum saw the only two written constitutions ever implemented in this country, and it saw them both discarded. It saw government by Parliament, by a Lord Protector – a title which hadn’t been used since the Duke of Somerset’s dramatic fall from favour under Edward VI in 1549 – and by a junta of major-generals. It saw a battle to build a godly society in the aftermath of war and a frenzy of debate about exactly what it meant to live in one. The times called for courage, vision and sound common sense – a rare combination. ‘The worke of God is such, as must have men of wisdom in it,’ the Puritan preacher William Carter had warned Parliament back in 1642. ‘The enemies of God are crafty.’

The ten essays that make up Blair Worden’s thought-provoking new book are all concerned with men of wisdom and the ways in which they sought to counter the crafty enemies of God. Oliver Cromwell is the towering figure at the heart of God’s Instruments – pragmatic, tempted by the trappings of power and all the time trembling, as the regicide William Goffe put it to his fellow-officers, ‘att the thought that we should bee standing in a direct opposition against Jesus Christ in the worke that he is about’. But as the book’s subtitle suggests, there are other players, and Worden is as interested in the mechanics and morals of government and governance as he is in Cromwell himself.

One of the most fascinating essays in the book is ‘Cromwell and his Councillors’, an exploration of the council of state that kept a check on the Protector (their own view), or jumped to do his bidding (the view of his opponents in government). Our knowledge of the council is imperfect for two reasons: one, their formal meetings were sometimes supplemented by informal, unrecorded pre-meets; and two, alongside the surviving official minutes, clerks kept a ‘private book’, now lost, which held the sensitive stuff. In theory the council wielded enormous power. In practice, as Worden points out,

the destiny of Cromwellian England lay not at the council table, but in the decisions of the generals and of the captains and soldiers behind it … the council, however valuable to Cromwell as a source of assistance, mattered as a locus of power only because the generals sat on it.

Worden writes with inspiring scholarship and perceptiveness on providentialism, toleration, and the idea of a commonwealth. All ten essays have appeared before in various guises. Four date from the 1980s, when Worden was part of a movement in seventeenth-century studies that sought to reclaim Puritan religious conviction from the clutches of Marxist historians who dismissed religion as code for political ideology. The others are much more recent, but they still reflect the lasting legacy of that realignment in their determination to acknowledge piety as a driving force behind the revolution of the 1640s. He has tidied them up, made corrections here and there and, in five cases, expanded and revised them quite considerably.

This in itself would make them worth revisiting. But taken as a whole they have, in spite of the author’s modest disclaimer, a coherence that sheds so much light on Cromwell’s reign that it dazzles. And they show Worden determined to strip away our assumptions about the past and its language. What was meant in the mid-seventeenth century by phrases like ‘civil liberty’ and ‘religious liberty’, and what was the relationship between the two? Rather a tenuous one, it turns out. Does it make sense to argue that republican aims animated the revolution of 1649? Not really, no. Why were so many veterans who risked everything to topple Charles I happy enough with the idea of offering the crown to Cromwell? Because that was what happened when you got rid of a monarch – you didn’t invent another form of government, you just found yourself another king.

In the most substantial essay, the 103-page ‘Politics, Piety, and Learning: Cromwellian Oxford’, Worden explores the realpolitik of running Oxford University in the 1650s. The university was a natural target for reformers after it offered a home to Charles I and his court during the war. But reformation has never come easily to Oxford. Worden shows us the factional infighting, the toadying and lobbying, the Puritan exasperation at the long hair and disorderly conduct of the students – who would have thought? He offers glimpses into the different ways in which music, experimental philosophy and naked self-interest occasionally broke down ideological and religious barriers between the dons. And in the end he concludes that it would take more than a revolution to effect a change. ‘The Puritans made a profound impact on Oxford … and the more they changed it, the more it remained the same.’

Worden’s central theme, the nature of the relationship between religion and politics in Cromwellian England, runs through the entire book. Even an essay on the Earl of Clarendon, which in its discussion of how royalists constructed the narrative of the civil wars and the Interregnum forms a curious tailpiece to the collection, picks away at that ‘permanently intractable feature of the age, the synthesis of religious and political aspiration’.

God’s Instruments is very much a book about ideas, about what they mean to us and what they meant to another age. At times Worden assumes a thorough knowledge of the events of the mid-century: readers who can’t tell their Instrument of Government from their Humble Petition and Advice might be stretched. That’s no bad thing, although if you need a primer, look no further than the same author’s admirably lucid The English Civil Wars: 1640–1660.

But for those possessed of a desire to understand this moment in history when Parliament ‘was a word … that carried armies in it’, God’s Instruments is quite simply indispensable.