For the expenses of so large a household, and the maintenance of this fine library, not to mention a palace that was being built and churches that required adornment, the mere revenues of the duchy could not have sufficed.
Federigo owed his wealth to his engagements as a general.

Military service formed his trade.

'In 1453,' says Dennistoun, 'his war-pay from Alfonso of Naples exceeded 8,000 ducats a month, and for many years he had from him and his son an annual peace-pension of 6,000 in name of past services.

At the close of his life, when captain-general of the Italian league, he drew in war 165,000 ducats of annual stipend, 45,000 being his own share; in peace, 65,000 in all.' As a Condottiere, Federigo was famous in this age of broken faith for his plain dealing and sincerity.

Only one piece of questionable practice--the capture of Verucchio in 1462 by a forged letter pretending to come from Sigismondo Malatesta--stained his character for honesty.