It was as recreant vicars of the Roman church that the papacy chose to proceed against the Malatesta, and formally it was the forfeiture of this title which precipitated their fall. Among the earliest of signori in the Papal States to receive the office of vicar, they were among the last to lose it. To trace the development of the institution under them is, in part at least, to trace a history of the institution itself.

As elaborated during the fourteenth century, the vicariate in temporalibus represented in a new form the customary readiness of the popes to make a bad bargain rather than no bargain at all with powerful subjects who might later, under different circumstances, be less disposed or less able to resist their authority. It was granted normally to lords, tyrampni, whom it was designed to convert from formal officers of city and commune into formal delegates of the pope. The popular sources of the despot's powers were not always explicitly repudiated, but, in early days at least, the investiture of a vicar was sometimes preceded by token surrender of the city to a papal representative and by an oath of fealty from the citizens; while even later the pope quite commonly addressed letters to the subjects of a signore, now vicar, commanding them to obey the new papal officer. By pope and despot alike the vicariate was conceived as a privilege, and this character it long preserved; it was usually awarded or renewed on petition, and in many cases renewal had also to be purchased.