Focusing on early Carolingian frontier’s practices, the paper opens discussing the topic’s significant scholarship, debating influential work of the past up to the developments of the last years. Afterwards, the frontier’s role between Antiquity and the Early Middle Ages is discussed in detail, focusing on fortifications, violence, and terminology. Finally, the Alpine clusae at the end of the Lombard rule, as well as the Carolingian expansion to the east are taken in exam. Due to a fortunate conjuncture of different sources, the two case-studies enable to enlighten important aspects of early medieval frontiers.