The deed was done, and the Holy Roman Empire, which lasted a thousand years, and only in the days of our fathers was shattered by the fist of Napoleon, was established, or (as Alcuin and Leo would have said) was re-established in Europe. It was a revolution, no doubt, that was enacted on that morning of the 25th of December 800. It could not have been justified out of the Digest or the Code. According to all the maxims of legitimacy which had prevailed for many preceding centuries, Charles was an usurper and Leo an intermeddling traitor. And yet, if one could go back still earlier to the first days of the empire, the bestowal of the imperial title on Charles was not so utterly lawless a proceeding. The Roman Imperator in those early centuries was not by any elaborate process elected, but was always acclaimed. Acclaimed by the army, it is true, but also by the people, and there were doubtless many soldiers of the _militia cohortalis_ [the imperial guard] of Rome present among the crowd who shouted for life and victory to the peace-bringing emperor. When acclaimed by army and people the Cæsar was, or ought to be, accepted by the Senate; and there are some indications that after centuries of suspended animation a body calling itself the Senate was at this time existing in Rome and consenting to the elevation of Charles. And these bodies, Senate, people, army, however insignificant in themselves, were at any rate Roman: they belonged to the true old Rome; they trod the forum of the republic, and looked up to the Palatine of the emperors; they were not like the bastard Romans of the Bosphorus, who chattered in Greek and wore the robes of Asia, but who had usurped for many centuries the profitable trademark of the Senate and People of Rome. So, though there was but one precedent--and that the bad one of Maximin the Thracian--for conferring the dignity of emperor on a man of purely Teutonic descent, and though it is quite impossible to find a place for the chief actor, the Bishop of Rome, in the drama as played by all the earlier Cæsars, we may on the whole conclude that Charles became Roman Emperor by as good a title as any who had worn the purple since the days of Theodosius.[65] What were the chief causes which led to this great change in the political constitution of Europe? They have been already hinted at, and we shall probably not be wrong in enumerating them as follows: