As we are increasingly confronted with actors operating outside “normal” state-centric networks, studying a period when states paradoxically consisted of non-state networks can be very enlightening. I have mentioned the study of medieval England in a previous post. My third historical network analysis is that of the medieval German Empire, in particular during the crusades.
One of the largest military undertakings of the Middle Ages was mobilization of the Third Crusade, the prelude to which was the subject of the film Kingdom of Heaven 2005. In July of 1187, Saladin, ruler of Syria and Egypt and founder of the Ayyubid dynasty, had destroyed the armies of the Christian kingdom of Jerusalem at the Battle of Hattin. When confirmation of this defeat reached the western European powers, they began preparations for a campaign to aid the kingdom, and continued with greater urgency when confirmation arrived of the loss of Jerusalem. What audiences today remember most about the Third Crusade is the military contest between Saladin and Richard “the Lionheart” of England, usually as the backdrop to Robin Hood fiction.
However, armies from the German empire played a significant, if ultimately truncated, part, in the counter-offensives that were launched in 1189 and 1190. The main imperial army, under Emperor Frederick I, is thought to have numbered about 15,000 fighting men, and marched overland through the Balkans and modern-day Turkey, surviving multiple enemies until the emperor accidentally drowned within a couple weeks of Syria (it ranks as one of the most ironic deaths of the Middle Ages). Other groups sailed from North Germany, or from Italy, and arrived in time to join the fighting around Acre, in modern-day Israel.
German scholars have long recognized that networks determined the nature of power and its application in the medieval German empire–we have some brilliant monographs on the elite who had dealings with the German emperors, and what the patterns of these associations mean.  However, to date no one has shown much interest in using network science to analyze this data, although several long-standing debates revolve around the very questions network science is designed to answer. For example, in the German realm especially, political power was contested and particularly influenced by faction and interest. It follows, then, that any German monarch leading a large army out of Germany would use troops drawn from his own lands particularly, and not so much troops from his rivals or those dissatisfied with the power or behavior of the emperor’s family.