Pirenne and other incarcerated professors set up schools and gave lectures in the camp’s society of Europeans from the countries affected by the war. However, as you might guess, such lectures drew the attention of the German officers who limited what was said and who eventually had the Belgian transferred elsewhere.
He had his intercessors because of his international reputation as a scholar. Princeton U. asked for his release, and so did President Wilson (a Princeton alumnus and the university’s president for four years), King Alfonso XIII, and the Pope. Eventually, the Germans sent him to the small German town called Kreuzburg on the Werra, where he was largely free to roam as long as he reported daily to Herr Burgomeister. There Pirenne lived in a house, eventually met a number of prominent people, and had conversations with the regional superintendent of the Lutheran Church. And all the while he read and did research on a topic dear to his heart: The history of Europe.
From the very outset of his imprisonment, Pirenne lived by a driving motivation: It’s better to kill time than to be killed by time. In other words, the guy strove incessantly to be the best he could be. In Holzminden, for example, he engaged Russian prisoners to learn their language and to discuss their country’s history. That was his nature. As he writes in is Souvenirs de Captivité, “I decided immediately that I could never hold out against the monotony of my detention unless I forced myself to undertake some definite occupation….”
So, Henri went on to research and write during his incarceration, went on to learn Russian, and went on to write his A History of Europe. What did you do today? What will you do tomorrow? Yes, I know, inconveniences keep interrupting you, And just when you think you have the time to do something important, you find yourself in an inconvenient place.