A renowned intellectual humanist and civil leader in Urbino on top of his impeccable reputation for martial skill and honour, he commissioned the construction of a great library, perhaps the largest of Italy after the Vatican, with his own team of scribes in his scriptorium, and assembled around him a large humanistic court in the Ducal Palace, Urbino, designed by Luciano Laurana and Francesco di Giorgio Martini.

Guidantonio da Montefeltro, lord of Urbino, Gubbio and Casteldurante, and Duke of Spoleto acknowledged Federico as his illegitimate son.

After Piccinino's resignation, he went to Pesaro to defend it against his great enemy in the Marche, Sigismondo Pandolfo Malatesta, lord of Rimini.

[2] In the pay of the Sforza—for Federico never fought for free—he transferred Pesaro to their control, and, for 13,000 florins, received Fossombrone as his share, infuriating Sigismondo Pandolfo Malatesta.

Malatesta profited from his injury to obtain the position under Sforza, whereupon Federico in October 1451 accepted instead a proposal by Alfonso V of Aragon, King of Naples, to fight for him against Florence.

After the loss of the eye, Federico – no stranger to conspiracies and one of the leaders that inspired Niccolò Machiavelli to write Il Principe – had surgeons remove the bridge of his nose (which had been injured in the incident) and eyelid.

In 1478, Federico was involved in the Pazzi conspiracy; in the aftermath of the failed plot, he carried out attacks on the territory of Lorenzo de' Medici.

The Duke had lost the mate he described as "the delight of my public and private hours"; a contemporary, speaking of their relationship, had called them two souls in one body.

He imposed justice and stability on his tiny state through the principles of his humanist education; he engaged the best copyists and editors in his private scriptorium to produce the most comprehensive library outside of the Vatican; he supported the development of fine artists, including the early training of the young painter Raphael.

Federico commissioned for himself a studiolo (a small study or cabinet for contemplation) in both his palace at Urbino and that at Gubbio; both are celebrated for their trompe-l'œil decoration executed in marquetry.

Commentators insist on his dedication to the well-being of his soldiers explaining why his men proved loyal to him and why Federico technically never lost a war.