A major work of historical fiction.
I have read a great deal of Tudor history both academic and popular and I can say without qualification that Mantel's reconstruction of Cromwell is the most convincing fictional rendering of that particular mind I have encountered. What she does with the present tense is divisive among readers but I think it is exactly right for this material — it removes hindsight, forces immediacy, and makes the reader live inside Cromwell's perpetual uncertainty about what comes next. The historical liberties she takes are few and intelligently considered.