Government in the rich and powerful cities was constantly changing hands. In Rome itself, where the situation was made more difficult and complicated than anywhere else, because of the Pope and his claim to governing power, the changes were bewildering. The power of the aristocracy was much broken in the middle of the fourteenth century when Rienzi, "Last of the Tribunes," led the democracy. Rienzi was the friend of Petrarch, and Bulwer Lytton has made him the hero of an exciting novel. But the Pope returned to Rome from Avignon in 1367, and though there were for a while rival Popes in Avignon and in Rome, yet by the end of the century the republican government of Rome had been overthrown and the Pope had gained supremacy. He never really lost it. At one moment in the {226} fifteenth century the forces of the King of Naples took and sacked Rome itself. At another the Pope had to flee before his own barons. But he soon came back. One of his successors only saved himself from these same barons, or their descendants, by the aid of Naples. Nevertheless by the end of the century, which is the date of the end of the present story, the power of the nobles had received what really was its death blow. In Florence and in Rome their chiefs were simultaneously massacred. The Papal power was finally established. Venice, as we have seen, was for a while by far the strongest and the most wealthy of the Italian States. But now the new naval power in the Mediterranean, the power of the Turks, was limiting and diminishing her strength, and shortly before the end of the fifteenth century two Portuguese navigators made a discovery of which the effect was to limit and diminish her wealth. If you will look at the map of the world you will see how far the Continent of Africa extends southwards, and you must understand that at the time about which our story is telling us now, no one knew how far southward this Continent stretched. Hitherto no navigator had come to its southern end. Many had gone sailing, sailing, south, but still that land was always there, on their left hand, on the eastern side, until these Portuguese navigators, Bartolomeo Diaz and Vasco da Gama, sailed yet further than any before them, came to the southern end of the great Continent, and found an open sea over which they might sail eastward. They had rounded what afterwards was named the Cape of Good Hope.