Heart of Europe is one of those books which can rightfully be called a tome: a sprawling history of the Holy Roman Empire from its beginnings with Charlemagne to its dismantling by Napoleon to the ways in which the Empire has been used and abused by modern historians and politicians. I'm giving it a four stars out of five largely out of sheer respect for the mastery of such a wide range of sources and scholarship that are needed to write such a work. Peter Wilson is clearly steeped in knowledge about central Europe, and I think his central argument—that the HRE shouldn't be dismissed as a ramshackle, inefficient failure because it doesn't look like a modern nation state, but rather assessed on its own terms as a decentralised system that embraced consensus, diverse identities, and local variation—is broadly persuasive.
However, Wilson's writing perhaps mimics the HRE a little too much. By eschewing the Grand Narrative/Big Man view of history (again, something I'm broadly sympathetic to), Wilson must fall back on exploring the HRE through the development of ideas and institutions. That could have worked, but Wilson's tendency to mention every name, date, battle, or other event that relates to the matter at hand means that it's sometimes hard to see the wood for the trees. I found it a bit of a slog at times, and I'm a historian; I'm pretty sure Heart of Europe would be very tedious for the general reader, particularly if they have no prior knowledge of the history of the HRE. Still, as an encyclopaedic guide to the HRE and its historiography, it's sure to become the standard reference work on the topic.