At the very start of the English Civil Wars, very few could have imagined that the country would soon become a republic. Yet just a decade later, King Charles I stood trial for treason, and was executed, in one of the most radical and incendiary acts of those turbulent years.

Practically alone in his republicanism at the start of the war was Henry Marten, MP and future regicide. But soon he gathered around him a group of radical parliamentarians that included William Strode, the parliamentary firebrand, the formidable soldier Alexander Rigby and Sir Peter Wentworth, Marten's best ally in the Commons, to form the nucleus of a group which would ally itself to a popular movement outside Parliament to agitate for the King's trial.

In The Fiery Spirits, the renowned historian John Rees tells the story of Marten's radical allies and their pivotal role in the Civil Wars. A brilliant work of narrative history, The Fiery Spirits tells the story of the radicals who brought the nation to the brink, whose dream of a kingdom without a crown, where the people were sovereign, set Britain alight.