i.
While the influence of the Popes was thus weakened in their states beyond the Apennines, three great families, the Orsini, the Savelli, and the Colonnesi, grew to princely eminence in Rome and its immediate neighborhood.

They had been severally raised to power during the second half of the thirteenth century by the nepotism of Nicholas III., Honorius IV., and Nicholas IV.

This nepotism bore baneful fruits in the future; for during the exile at Avignon the houses of Colonna and Orsini became so overbearing as to threaten the freedom and safety of the Popes.

It was again reserved for Sixtus and Alexander to undo the work of their predecessors and to secure the independence of the Holy See by the coercion of these towering nobles.
In the States of the Church the temporal power of the Popes, founded upon false donations, confirmed by tradition, and contested by rival despots, was an anomaly.

In Rome itself their situation, though different, was no less peculiar.