Auxiliaries, which are the other useless arm, are employed when a prince
is called in with his forces to aid and defend, as was done by Pope
Julius in the most recent times; for he, having, in the enterprise
against Ferrara, had poor proof of his mercenaries, turned to
auxiliaries, and stipulated with Ferdinand, King of Spain,(*) for his
assistance with men and arms. These arms may be useful and good
in themselves, but for him who calls them in they are always
disadvantageous; for losing, one is undone, and winning, one is their
captive.

(*) Ferdinand V (F. II of Aragon and Sicily, F. III of
Naples), surnamed "The Catholic," born 1542, died 1516.

And although ancient histories may be full of examples, I do not wish
to leave this recent one of Pope Julius the Second, the peril of which
cannot fail to be perceived; for he, wishing to get Ferrara, threw
himself entirely into the hands of the foreigner. But his good fortune
brought about a third event, so that he did not reap the fruit of his
rash choice; because, having his auxiliaries routed at Ravenna, and
the Switzers having risen and driven out the conquerors (against all
expectation, both his and others), it so came to pass that he did
not become prisoner to his enemies, they having fled, nor to his
auxiliaries, he having conquered by other arms than theirs.

The Florentines, being entirely without arms, sent ten thousand
Frenchmen to take Pisa, whereby they ran more danger than at any other
time of their troubles.

The Emperor of Constantinople,(*) to oppose his neighbours, sent ten