Most modern governments have political structures and legal procedures derived in a long evolution from those of the ancient Roman emperors, with a shallow overlay of modern democracy. The main exceptions, the Anglo-American countries, have legal procedures derived primarily from a partially independent evolution in England, but still with substantial influences from the old Roman autocrats. Political ideas and legal procedures are closely related, and versions of these derived from the Roman Empire have dominated most of European history.
I have started writing a history of this legal and political tradition. It starts with the Year of the Five Emperors, the rise of the Severan dynasty, and under that dynasty the first two major jurists (legal authorities) in the later Roman legal tradition, Papinian and Ulpian. It continues through the famous Codes of the emperor Justinian (as compiled by his jurist Tribonian), to the birth of universities in Western Europe upon the rediscovery of Justinian's codes, through the political philosophies of Bodin and Hobbes, to the Reception of Roman law into Western Europe, to the Code Napoleon, the German and Russian legal codes, and modern dictatorships based on the political and legal ideas of Rome. This will be a sprawling history and indeed I will probably never finish it. But meanwhile I will post a good bit of it to this blog, starting with the next post. I expect to proceed largely in temporal order, but no guarantees. Quite a few of my blog posts over the next two years may be part of this series. It should be quite enjoyable as well as provide unique insights into the history of political forms and constitutions.