Main Stage: 55 Days

God’s Englishman, Oliver Cromwell (a mightily transfixing, but also troubled, Douglas Henshall), stands firm in his vision of liberty for all under a constitutional monarch, while the anointed king, Charles I (a brilliantly cast, effete and scathingly superior Mark Gatiss), pours scorn on the kangaroo court and its sober-suited executives.

For while Brenton, with characteristic broad brush strokes, and a steely grip of narrative structure, excitingly evokes the factionalism among the regicides (Gerald Kyd as the Levellers’ leader and Abigail Cruttenden as Lady Fairfax, wife of the commander-in-chief, are particularly well drawn), the play also resonates as a metaphorical battle between suits and intellectuals.

The re-birth of Howard Brenton as a substantial historical dramatist – although you can trace the evolution, from his earliest, scabrous plays about public figures and murderers – is one of the great theatre stories of our time. And there’s something about the electrifying show-down scene between Cromwell and King Charles in the latter’s prison cell that brings us full circle in his dramatic career.

At its considerable best, the play depicts the political process with clarity and vigour. And taking his cue from Schiller, who invented a meeting between Elizabeth I and Mary, Queen of Scots, Brenton adds a fictional scene in which Cromwell desperately tries to persuade Charles I to save his neck.

Douglas Henshall, however, brings a persuasive mixture of bustling vigour, religious fervour and moving self-doubt to Cromwell, and takes the audience completely by surprise in the brilliantly disconcerting penultimate scene.

Howard Brenton’s new play 55 Days also heads towards a violent foregone conclusion. It is set during the English civil war at the moment when Parliament is voting whether Charles I should be tried. It ends with his execution. Brenton helps one experience this chapter in history as the extraordinary, unthinkable, bloody turning point it was. The parallel with today is in the uncertainty of the times, the sense of a country on the brink of disaster; this gives the play its charge.

Howard Davies directs with unerring panache. Ashley Martin-Davis’s design is resolute, grey, puritanical. Only Charles is dressed for the 17th century in Antwerp lace, buckled shoes and cloak, a hint that he is history while the others, in their suits, serve the future. He is exquisitely played by Mark Gatiss, a balance of courage, frivolity and bloody-mindedness. His royal error is to believe himself above – way above – the law, answerable only to God. The word “cavalier” was made for him.

It is a play, as you would expect from Brenton, of intellectual grip but with more head than heart. Its greatest strength is in its exploration of authority – divine and otherwise (a good subject for a writer who has such authority himself). Both Charles and Cromwell believe God is directing them. But who is “God’s Englishman”? Step forward Douglas Henshall as Cromwell. He is charismatic; there is an amazing relaxation at the centre of his performance as he shows us what leadership is. We witness his changes of heart – his struggle between the humane desire to compromise and vain, violent impetuosity. The play’s most masterly scene describes what never happened: Charles and Cromwell meet over a bottle of wine and find nothing – and then everything – to say.