ABSTRACT
The Greeks (as they were universally called in the west) were the major interlocutors of the Franks by the early ninth century. Between the late 790s and the 820s there was an embassy moving from one to the other nearly all the time, a constant exchange of dozens of high-ranking figures. There were always embassies at Aachen, Charlemagne's capital, from everywhere, it is true; but the ones from Constantinople were held to be the most important: it was they, for example, whom Louis the Pious received most prominently when he succeeded Charlemagne in 814, and in 817 the envoys of the amir of Cordoba had to wait three months while Louis dealt with an embassy from Leo V that had arrived later.2 The Franks, in their own eyes (and not wrongly), were by far the dominant power in the west; in 800 their king was crowned imperator et augustus by the pope. Only the other imperator, in Constantinople, was to them in any sense their equal. And the Byzantines seem to have recognized some of this themselves, for they did address the Frankish emperor as basileus or imperator, on several documented occasions during the century from Michael I's reign onwards; their major concern was to retain a monopoly of not the title, but its attachment to the word 'Roman', basileus ton Romaion, which Michael I pointedly put on his coins. It appears, that is to say, that as long as Romanity belonged to the east, the west could have emperors too.3
