Joseph F. O’Callaghan is arguably my favorite non-hispanic reconquista scholar, as his works on this subject are second to none. In this book, A History of Medieval Spain, Joseph F. O’Callaghan goes into incredibly detail on the history of Spain from both the Christian and Muslim sides, in a comprehensive way. This is a scholarly research book, so some people may find it a bit boring and dry when it comes to subjects like civil society, economy, and government, and the ongoing cultural shifting happening throughout medieval Spain.
I would first recommend people to read his book Reconquest and Crusade in Medieval Spain. Since its a much easier and shorter read (and highly entertaining), also that book is only just an overview, this book goes into way more detail. Reconquest and Crusade in Medieval Spain just scratches an itch, while A History of Medieval Spain, goes full guns blazing.
This is a fairly large book. With its timeline starting with Roman Hispania, albeit brief, to the Visigoth Kingdom. In fact, I was surprised to see how much content was included about the Visigoths!
Of the many books I’ve read about medieval Spain, I have to say this is the absolute definitive book for anyone wanting about the incredible history of the reconquista.