Do you know it occurs to me part of my struggle to find novels written from a non-Royalist perspective about the English Civil War period may be that Cavaliers write novels (Wrong but Wromantic to the last) but Roundheads write biographies. I've read several wonderful biographies of interesting people from that side. Maybe I should recommend them instead of whining about a lack of novels:
The Porcupine by John Carswell, a life of Algernon Sidney. There's a longer, more complete biography of Sidney by Jonathan Scott, but Carswell's is the most readable I think. Scott's is more of a reference.
Free-Born John by Pauline Gregg, a life of John Lilburne, the great Leveller. I used to have a sticker of Lilburne on my laptop. I put it over the manufacturer's logo. I made it myself. I haven't made a Lilburne post yet, partly because it's been ages since I read this, but I'd like to. Maybe I'll reread it. Honestly this should be a joint biography of John and his wife Elizabeth, and nearly is.
The Tyrannicide Brief by Geoffrey Robertson, a life of John Cooke, the prosecutor at the trial of Charles I. I read this one on the recommendation of @suzannahnatters some years ago!
Memoirs of the Life of Colonel Hutchinson by Lucy Hutchinson. This one obviously isn't a modern biography, she's contemporary to the period; and it's a little weird that it's easier for me to find a biography by than about a seventeenth-century woman. But her biography of her husband is also very much about her own experiences. And she's fascinating.
And not all historical novels are Royalist-leaning. Rosemary Sutcliff's The Rider on the White Horse is about Thomas Lord Fairfax, from the perspective of his wife. It's quite good.
I have a book called The King's Revenge out from the library but I haven't read it yet. There's also Act of Oblivion which made a big splash (as these things go) recently, but the thriller-to-history ratio looked a little high for me. Might try it sometime though.
