The land of Provence has a history quite separate from that of any of the larger nations of Europe. Its independent existence has its origins in the frontier nature of the dukedom in Merovingian Gaul. In this position, influenced and affected by several different cultures on different sides, the Provençals maintained a unity which was reinforced when the region was made a separate kingdom during the Carolingian decline of the later ninth century. When Boso of Provence acquired the region in 879, it was known as Lower Burgundy until it was merged with Upper Burgundy in 933 to form the Kingdom of Arles. The counts of Arles began calling themselves "count of Provence"; although in name vassals, they were de facto autonomous princes. After 1032, the county was part of the Holy Roman Empire.