Starting from the late 11th century, dependency of the Byzantine Empire on the naval forces of Republic of Venice and, to a lesser extent, Republic of Genoa and Republic of Pisa led to the predominance of Catholic merchants in Byzantium (they were getting major trading concessions starting from the 1080s), subsequently causing economic and social upheaval. Together with the perceived arrogance of the Italians, it fueled popular resentment amongst the middle and lower classes both in the countryside and in the cities.