 Complete the following phrase:  Towards the end of this period Venice had accumulated a large and powerful fleet. Although still nominally a vassal of the Byzantine Empire, Venice was increasingly independent and a rival of Byzantine for primacy in the Eastern Mediterranean. Rather than depending on the Byzantines for their survival, the Venetians held, with their fleet, the balance of power, and was able to use it to leverage concessions from both the Byzantines and their rivals in Western Christendom, profiting from both. In return for Venetian aid against the Normans, in the 