After the fall of Napoléon, many alpine countries developed heavy protections to prevent any new invasion. Thus, Savoy built a series of fortifications in the Maurienne valley in order to protect the major alpine passes, such as the col du Mont-Cenis that was even crossed by Charlemagne and his father to defeat the Lombards. The later indeed became very popular after the construction of a paved road ordered by Napoléon Bonaparte.