King Charles III by Mike Bartlett at Cambridge Arts Theatre until Saturday, October 24. Review by ANGELA SINGER.

The third Bonny Prince Charlie is on the throne. He’s pushing his 70s but he’s still fighting fit. In fact the first thing he does is to pick a fight with the House of Commons.

Interestingly, after the way they have treated him, he leaps to the defence of the Press. The Labour Government wants to pass a law regulating them. Charles says this is dangerous censorship and could stop journalists uncovering corruption.

When the Prime Minister refuses to change the Bill, Charles refuses to sign it. He dissolves Parliament and causes riots across the land.

This is Mike Bartlett’s cleverest play so far. It is beautifully written, in iambic pentameter, so it has the rhythm and syntax of a Shakespeare text. This sounds pretentious but it works. In modern English, we do hear the lines but an antique, regal tone over them is thrown. (It’s nothing like as banal as that but you get the gist). It’s so fast paced and so funny that it all blends in. There is a stirring rhythm to the whole piece.

A stark set of the bare brick walls of a castle, places us apart from the world in the confines of the palace. We are inside this royal family. A world is created. But why this production is so worth seeing, are the inspired performances.

Robert Powell has Charles’ demeanour and just a shadow of his voice, he emphasizes particular words, the way Charles does, but this never descends into parody. This is a warm, passionate, yet measured performance from a master that is utterly engaging.

Charles says politicians are transient, fickle and fleeting. Being a king is a life-long commitment. He has been schooled all his life for it. He has the right to dissolve Parliament. Somehow, it almost seems logical. It certainly is to him.

Kate, William and Harry are a joy. They carry the humour of the play and there is a lot of it.

These are characters all created with glorious panache, each has the deportment and voice through them like Brighton rock.

Kate (Jennifer Bryden) has diction, delivery and deportment to eat in slices. It’s a lovely twist that in the end the demure newcomer to the family is the one who steers the sinking ship into a safe harbour.

In a lovely subtlety, William (Ben Righton) has a demeanour reminiscent of the young Prince Charles. Well, he would, wouldn’t he? Harry (Richard Glaves) is an amusing, blend of soldier and unworldly royal.

Plaudits, too, to Beatrice Walker for divers cameo roles, including Princess Diana and television producer, and also to Parth Thakerar for playing everyone from a kebab seller to an archbishop.

The play has shades of Macbeth and delicate hints of Hamlet. It’s a brilliant, ensemble production and a magnificent piece of theatre.