If I were reviewing this is a fantasy book, I would critique is for being repetitive. After all, this is book four in which Lancaster and York fight, kings get captures, kings get killed, people don't have heirs at the appropriate times, and battles are fought over the exact same thing that they were waged a few years ago. However, if this is not a fantasy novel, so I can't blame Iggulden if Ravenspur started to feel repetitive in places. This is, after all, what really happened, or at least the broad strokes are. For some thirty years, the houses of York and Lancaster fought back and forth over the throne of England, and devastated the population in the process.
Perhaps the most interesting facet of the writing of Iggulden's Wars of the Roses historical fiction series is how, while the POV character switches frequently within each book, each novel seems to focus on a different character for its primary storyline, the character with whom the reader is meant to sympathize. In the first book, it was Margaret of Anjou. In the second book, it transitioned to York, particularly King Edward. With the third book, the series began to transition its focus to Earl Warwick, Richard Neville.