I got this book from the publisher (via Netgalley) for review
Tudors is the second book of Peter Ackroyd's History of England. I haven't read the first one, Foundations, but I wasn't lost. Since I haven't read it, I can't say if you really should read it before reading this one. Clearly it's not required reading to understand this book, since I read this one with out any issues. (Note: I did just finish Elizabeth of York by Alison Weir, which spans the time right before this book starts and that might have something to do with it). It is well written, although the writing style is different from anything I've read before and it made it a little harder to get into at first.
This book focuses both on the Tudors and the Protestant Reformation in England. I know quite a bit about the Tudors but I'd never really thought about the Protestant Reformation in England. I knew before reading this book that it was started by Henry VIII, at least partly so he could divorce his current wife and remarry. I hadn't really considered that there might be more to it than that. It is true that the Reformation was started by Henry VIII, but Edward IV and Elizabeth I continued what he'd started (although Mary I tried to undo alot of what both Edward IV and Henry VIII had done, since she was Catholic.
This book is also about the Tudors, ranging from Henry VIII to Elizabeth I. The first half of it is more about the Reformation, but the latter half is divided more evenly between the to topics.