As a person who neither knew nor had any interest about Middle European history - let alone Prussia; Iron Kingdom was not only exceptionally informative but comes close to the most interesting historical books I have read. The book is not only informative but it is written in a way where you cannot help but be pulled in. The historical characters and political conflicts and the constant change Prussia makes for fun reading.Clark pulls no punches in this book, he goes straight into the history, quick-smart. You are being taught something every page and every paragraph. From the very beginning to the very end the history of Prussia comes to life. It delves into all aspects of society, from: military, politics, religion, diplomacy, religion, domestic law and culture - even the representation and influence of women. The author presents the history and the short biographies of the rulers. It tries to paint an ever changing political atmosphere of Europe; it does so in a way that you think have gathered some rational understanding on how the rulers saw their political landscape, and how the Prussian political environment influenced the way that the ruler and also the future heir formed and practiced their political views and their governance over it. For example, Fredrick the Great Elector was born and raised during the 30 year old. As such, he was moved to ensure his safety. Clarke then forms how he believes that the different environments Fredrick grew up with and discusses why he believes those environments shaped and constructed his ultimate views on how to govern Prussia. Clarke believes that the almost cosmopolitan up-bringing significantly changed Prussia into a greater and a greater structured empire. For example, Fredrick became dedicated in the way soldiers were trained. From the years in the Dutch Republic he - as Clarke writes - he forms an appreciation of the discipline, manoeuvres and top of the art weaponry among the Dutch army. From this, he re-imagined the Prussian soldier. From this, Clarke represents how Prussia cemented itself in history, writing not in the normal predictable deterministic way that some historians write in, but writing in a way to present and convey how a European empire was gradually formed by one boy and the ideas he formed via his environment. The biography may stretch the truth, of course. Yet it turns history in what it is, and that it is: life. Not a historical figure but a real person, with his own independent way of thinking.It also explores the constant changing of cultural and religious values, which were quite enthralling. Clarke writes in length about the how and why the conflict of the Calvinists and the Lutherans, and how this conflict help ignite a new form of religious movement within Prussia. He talks about the conflict both on the political side and the unrest amongst the citizens. Then Clarke discusses how this sparked Pietism as a possible solution to the religious conflict, and he details how this movement conceptualized throughout Prussia; changing not only religious beliefs and practices but also cultural and societal change. For example, the monarchy adopted the Pietist way by opening Pietists military schools throughout Prussia. The Pietist movement placed the individual as scared and gain fulfilment through and within the individual - breaking away from the ecclesiastical establishment. It place pinnacle importance on the self discipline by the individual and for the individual and the importance of the experience of life through the individual; which creates an ideal belief system to nurture the European Enlightenment.Clarke most intriguing chapter - for me, was on the enlightenment and how Prussia due to the monarch and the current views of his people, greatly influenced it. Fredrick the Great was a strong and devoted believer of a progressive, more human empire. For example, he virtually made torture illegal, due to its barbarity, plus he concluded that the practice generated false information. He even allowed for talks and phamlets about questioning the monarch itself. Although he was so loved, even Kant proclaimed one could live under an enlightened monarch. By having a progressive monarch and a movement that placed its value within the individual itself and and the idea one can work upon themselves and archive Christ within himself; is it no wonder how Kant developed his philosophy?There are many, many things I have not discussed. I have written about the things that were most interesting to me.I would recommend this book to layperson that has only a minor interest in European history, or any interest in western political/philosophy thought. The book is fluent and easy to understand. No historical prerequisite of Europe is needed - although there many wars, battles and treaties; yet a quick google will help with the basics. This book has made me aware of the importance of an empire, which seems completely forgotten and unknown within my culture. It has created a thirst for European history, which something I will undertake with vigor. So if a book can create such excitement about something I had absolutely no interest in me, which know creates a very strong interest to not only to Prussia's history but to all European past; it definitely deserves 5 stars!