In France and abroad, all the components of higher education were caught up in the war. Old or recent, French or foreign, their daily lives were permanently disrupted. The human and practical impact of mobilization being felt in various ways, depending in particular on whether they were in a non-occupied or occupied area (Lille, Belgium), how did law schools (and their libraries, which with the Third Republic in France became the support of the scientific mission that the faculties must also fulfill) adapt to the new context sparked by the Great War ? Where and how was law taught ? How were the faculties reorganized ? How did they function on a daily basis ? What were the forms of their involvement in the war effort ?