already had one.
Thus the Empire of Rome, which had died at the hands of Odoacer in 476, rose again in 800 as the "Holy Roman Empire." While its physical strength lay north of the Alps, the centre of its idea was Rome. It was, therefore, from the beginning a divided thing of uncertain power, a claim and an argument rather than a necessary reality (Wells, 1971, pp. 544-6).
What Charlemagne did not have was a strong administrative apparatus, principally because he built his empire by military rather than administrative means: "The enormous extension of the territories that recognized Charles as a king, the constant campaigning that did not always produce immediate results inevitably created new problems for the monarch and those who advised him (Bullough, 1966, p. 69). Gibbon says in this regard that Charlemagne's policies "compose not a system, but a series, of occasional and minute edicts, for the correction of abuses, the reformation of manners, the economy of his farms, the care of his poultry, and even the sale of his eggs (Gibbon, 1955, p. 35).
Currency reform under Charlemagne, which began before 800, was part of his efforts to stabilize the Frankish society and provide a means for the Frankish kingdom to be a part of the international community. It had not been so under the insular Merovingian society, and to the degree Charlemagne inherited that insularity, monetary policy was bound to be a problem for him. The gold standard of currency that had prevailed in Rome persisted not in Rome but in the Byzantine empire and among the Arabs of the eastern Mediterranean. In Western Europe, meanwhile, the actual gold content of coins, which had been standard under the Romans, had declined steadily. One reason the principal focus of coinage was on silver and not on gold in Charlemagne's domain was that there was far more silver than gold available in Europe during the ninth century. By the time of Clovis, Charlemagne's Mer...