The Fiery Spirits tells the story of the MPs in parliament and the protestors in the streets who played a pivotal role in the English Civil Wars. Through their stories, John Rees reveals the hidden history of the republicans who brought a desperate nation to the brink of revolution.

At the start of the English Civil Wars, very few could have imagined that the country would soon become a republic. Practically alone in his republicanism was Henry Marten, MP and future regicide. But he soon gathered around him a group of radical Parliamentarians that included William Strode, the parliamentary firebrand, Alexander Rigby, the formidable soldier, and Sir Peter Wentworth, descendant of a long line of opponents of monarchy. They formed the nucleus of a group that allied itself to a popular movement outside parliament to defeat the king politically and militarily.

In The Fiery Spirits, Rees tells how Marten and his radical allies overcame both moderate Parliamentarians and Royalists to change the face of England forever, establishing a kingdom without a crown.