Have a first look at Game of Thrones star Kit Harington in new BBC drama Gunpowder

He stars alongside Sherlock’s Mark Gatiss who has been cast as spymaster-in-chief Robert Cecil, with Lord of the Rings actress Liv Tyler playing Catesby’s cousin Anne Vaux who becomes suspicious of her relation's activities.

Shaun Dooley plays Sir William Wade, Lieutenant of The Tower and Cecil’s right hand man, with light relief (if that is possible) coming from comic actors David Bamber as the Earl of Northumberland and Kevin Eldon as Sir Joseph Hawksworth.

Also starring is Wolf Hall actor Edward Holcroft as Catesby’s friend and co-plotter Thomas Wintour, and Robert Emms as Father Gerard, a firebrand young priest.

Derek Riddell will play the plotters' target, King James I of England, with EastEnders actress Sian Webber playing Catholic sympathiser Lady Dorothy Dibdale. Spanish actor Pedro Casablanc plays the Constable of Castille, who was involved in the conspiracy.

The character of Guy Fawkes - which is not as big a part in this drama as you might think - is being played by Tom Cullen, an actor known to Downton Abbey fans as Lady Mary’s unsuccessful suitor Viscount Gillingham.

Harington has revealed that he was descended from Catesby and was keen in bringing his ancestor's story to the screen.

A contemporary portrait of Robert Catesby

A committed Catholic in Protestant England, the drama will portray Catesby's struggles to bring up his young son in an increasingly intolerant society, having recently lost both his wife and father.

He is angered by the suffering of his fellow Catholics, despite the pleas of Jesuit Father Garnet (played by Top of the Lake actor Peter Mullan) for peaceful protest.

The period thriller has been written by Ronan Bennett, himself a onetime Irish Republican activist, and will be directed by J Blakeson. It will air on Saturday nights on BBC1 this autumn.