This contribution offers an analysis of the relationship between the Republic of Venice and the Habsburg empire, which have long competed for the Upper Adriatic, thus creating an irregular “shifting boundary” between their properties. From the second half of the 16th century to the first half of the 18th century, supported by a series of cartographical documents, the geo-historical excursus highlights that, in the empire regions, the limes was conceived more as a border fringe, than as a boundary line dividing two political entities. Indeed, it included within itself regions of different jurisdictions, thus causing many fierce disagreements between the “Leone alato” and the “Aquila bifronte”.
