 Complete the following phrase:  Over the more than a thousand years of the empires existence, different titles were adopted and discarded, and many lost or gained prestige. At first the various titles of the empire were the same as those in the late Roman Empire. However, by the time that Heraclius was emperor , many of the titles had become obsolete. By the time of Alexios I , many of the positions were either new or drastically changed. However, from that time on they remained essentially the same until the 