Her quarrel with Genoa was scarcely finished when Pisa found herself at war with the Normans in Southern Italy, defending heroically the city of Naples and utterly destroying Amalfi, the wonderful republic of the South.[25] Certainly the might of Pisa was great; her supremacy was unquestionable from Lerici to Piombino, but behind her hills Lucca was on watch, not far away Florence her friend as yet, held the valley of the Arno, while Genoa on the sea dogged her steps between the continents.  Thus Pisa stood in the middle of the twelfth century the strongest and most warlike city in Tuscany, full of ambition and the love of beauty and glory.  For it was now in 1152 that she began to build the Baptistery, and in 1174 the famous Campanile, a group of buildings with the Duomo unrivalled in the world.

Meanwhile the Great Countess of Tuscany had died in 1115; more and more Italy became divided against itself, and by the end of the century Guelph and Ghibelline, commune and noble, were tearing her in pieces.  Tuscany, really little more than a group of communes devoted to trade, with the great feudatories ever in the offing, without any real unity, slowly became the stronghold of the Guelphs.  Only Pisa,[26] glorying in the strength of the sea and the splendour of war, was Ghibelline, with Siena on her sunny hills.  Now, having won Sardinia for herself, her nobles there established were, as was their manner everywhere, continually at feud.  The Church, thinking to make Pisan sovereignty less secure, supported the weaker.  Already Innocent III had, following this plan, called on the Pisans to withdraw their claim to the island.  And it was a Pisan noble, Visconti, who, marrying into one of the island families related to Gregory IX, recognised the Papal suzerainty.  Thus this family in Pisa became Guelph.  But the other nobles, among whom was the Gherardesca family, threw their weight on the other side, and so Pisa, who had ever leaned that way, became staunchly Ghibelline.[27]

The quarrel with Florence was certain sooner or later, for Florence was growing in strength and riches; she would not for ever be content to let Pisa hold her sea-gate, taking toll of all that passed in and out.  It was in 1222 that the first war broke out with the White Lily.  Any excuse was good enough; the bone of contention appears to have been a lap-dog belonging to one of the Ambassadors[28].  Pisa was beaten.  In 1259, nevertheless, she turned on the Genoese and drove them down the seas.  But the death of Frederic in 1250 was the true end of the Ghibelline cause in Italy.

What then did Pisa look like in these the days of her great power and prosperity?  She was a city, we may think, of narrow shadowy streets like the Via delle Belle Torri, full of refuse and garbage too, for then, as now in the remoter places, the household slops were simply hurled out of the windows with a mere guarda! called from an upper window.  And to the horror of less fortunate cities, these