The medieval union of Church and State, strengthened by the ties of morality and culture created by Christianity, founded on Christmas Day, 800, when Pope Leo III crowned Charlemagne emperor at Rome. From the first, it was an abstract concept; the relationship between Pope and Emperor was defined in various ways at different times, and but seldom agreed to by both; even the territorial extent of the Empire was always vague, though it may be stated roughly as comprising: all the German-speaking lands in Europe; certain territories to the west of these; and a shadowy claim, never substantiated, to the whole of Italy, though at one period the emperors had a firm hold on Sicily and resided there. Its history is inextricably bound up with that of the Papacy and of Germany; its throne, at first nominative, came to be elective, the electors being seven princes of the Empire, of whom three were the Archbishops of Mainz, Cologne, and Trier; it was abolished by Napoleon in 1806, many centuries after it had lost all vestiges of real political importance.