The proposal to bestow the Lordship upon Count Girolamo de' Riari by
purchase was warmly resented by the Florentines. Sixtus approached the
question in a most underhand and suspicious manner. He knew perfectly
well that negotiations were on foot for the acquisition of the property
and title by Lorenzo, on behalf of the Florentine Government.
Nevertheless he sent a secret mission to Galeazzo Sforza, Duke of Milan,
offering the handsome sum of fifty thousand gold ducats, with a proviso,
that the Duke should bestow the hand of his illegitimate daughter
Caterina upon Girolamo.

By way of adding insult to injury, Sixtus impudently sought a loan from
the Medici bank, with which to pay the Duke: this greatly offended
Lorenzo and all the leading men in Florence. What made the Pope's
conduct more despicable, was the knowledge that he regarded this matter
as the first step in a line of policy which aimed at supersession of the
Medici by the Riari in the direction of Tuscan affairs--himself being
Over-Lord.

The Pope's demand was refused indignantly by Lorenzo, who, in the name
of the _Signoria_, administered to his Holiness a severe rebuke for his
interference in the affairs of Florence. The relations between the two
Governments became strained, but Sixtus was perfectly indifferent to
opposition where personal interests were concerned.

His next move was the withdrawal of the Duke of Urbino, his relative,
from the military service of the Republic, and his appointment as
Commander-in-Chief of the Papal forces. This manoeuvre was regarded with
alarm by all the Italian States, and a league was formed by Florence,
Venice, and Milan, to check Papal encroachments.