Dissolution is the author's first novel; and, if we assume that he hasn't written anything else under another name, it's an unusually good start. Not many writers can get most things right at the first attempt, but Sansom has managed it.
The book is a historical whodunit, set in the reign of Henry VIII, when Thomas Cromwell is the King's right-hand man. Cromwell was actually running the country while Henry posed as ruler; and as head of the Church, of course.
You are likely to find the story somewhat puzzling, I suspect, if you don't know anything about the history of England at this time. And it will also help if you are interested in the Christian religion and the various schools of thought within it. Subject to that, Dissolution is a gripping read. At 390 pages I thought it might be a bit too long, but it held my attention throughout.
The protagonist, who tells the story as a first-person account, is the hunchback lawyer Matthew Shardlake. He is sent by Cromwell to the monastery at Scarnsea, to find out why Cromwell's previous commissioner got his head chopped off. He also has the job of persuading the Abbot to sign over his monastery and all its wealth to the King.
Needless to say, Shardlake eventually succeeds in all these things, and the series apparently continues in Dark Fire, which I have yet to read. Meanwhile, Dissolution is recommended.