Rome maintained her power and influence as long as the Mediterranean constituted the world; but, in proportion as the borders of the known world were enlarged, so did Rome lose the advantages which a central position had conferred upon her. Even during the latter days of the Roman empire Milan and Ravenna usurped the position once held by Rome, and the latter became the capital of the Ostrogothic kingdom, and subsequently the seat of the Byzantine exarchs. Rome, the city of the Cæsars, had fallen for evermore ! True, the emperors were succeeded by the popes, but the real masters of the “Holy Roman Empire” resided beyond the Alps, and only came to Italy to have their power consecrated. Even in Italy itself Rome ceased to be the leading town, its place being taken by Pavia, Florence, Genoa, Milan, Venice, Bologna, and even Turin. The unity of Italy has been realised in the course of this century, and, excepting a few Alpine valleys, its political boundaries coincide with its natural ones. It may surprise us that this unity should not have been established long ago, but the geographical configuration of Italy readily lends itself to the {187} establishment of small states. Its islands, its mountain-bound plains, and coast districts, shut off from the interior of the country by abrupt mountains, formed as many centres where populations of diverse origin were able to lead a life independently of their neighbours. Now and then the whole of Italy acknowledged a single master, but it only did so on compulsion. That spirit of nationality which has given birth to a united Italy only animated very few citizens of the mediæval republics. They might unite to resist a common danger, but no sooner was it past than they went their separate ways, or, still worse, fought amongst themselves about some trifle.