From the retirement of Dom. Michieli to the election of Vitale Michieli II. in 1156, two Doges, Pietro Polani and Dom. Morosini, presided over the growth of the lagoon state. In spite of troubles with the Adriatic pirates, the Hungarians in Dalmatia and the Paduans, new markets for Venetian commerce were won by the familiar process of squeezing the rival Cæsars of East and West. It was a time of building. The Campanile was finished, many churches were erected, and a hospital was founded for the mothers and widows of seamen fallen in the service of the state. Political theories that no longer correspond to realities are dangerous in proportion to the character and genius of those whose imagination they seize upon. Actually the Roman Empire had fallen to pieces, but so faithfully had the Romans wrought that it was regarded even by the northern invaders as an integral part of civilisation. The Church accepted and sanctified it, and the Holy Roman Empire continued to exist in theory until the wit of Voltaire and the big battalions of Napoleon destroyed the sham for ever. In the poetic mind of Dante, with his passionate aspiration for peace and righteousness, it became a beautiful but ineffectual ideal of a kingship over kings; an Emperor curbing the warring factions and states of Christendom and coercing such as threatened to break the common peace, so that the golden days of the _Pax Romana_ might be seen of men again. But the times were making for nationality and not for empire, and the attempts of the great emperors to realise their theoretical power were foredoomed to failure. [Illustration: S. MARCO--INTERIOR--CHAPEL OF S. CLEMENTE.]