Although Raoul van Caenegem claimed otherwise, he had very strong views on what legal history should be. In his opinion, legal history belonged to the disciplinary field of history, not to law. The legal historian should not only chronicle past evolutions of the law, but also explain them. To this purpose, van Caenegem himself turned to sociology, trying to work with types and models in order to generalise. Van Caenegem rejected the idea of a Volksgeist and advocated to look at the European context in a comparative legal history. Nevertheless, his ‘Europe’ was limited to the founding members of the European Union, joined by England. He constructed legal history as a history of power and preferred to study groups of law makers instead of individuals. In his legal history, the European ‘Second Middle Ages’, from 1100 until 1750, stand out as the cradle of the modern rule of law, with a special role for the cities of medieval Flanders. Although well-known for a leading handbook promoting the idea of the ius commune, the common law of Europe, van Caenegem actually deemed custom to have been the primary source of law in medieval Europe, whereas the role of the ius commune had been, in his opinion, overestimated. As he showed many times during his distinguished career, van Caenegem wanted legal historians to take part in current debates. In the end, his main lesson from legal history was a plea for moderation, as taking a sound idea to its extreme leads to absurd or unintended consequences.