Venice-born Pietro Barbo's adoption of a spiritual…

Venice-born Pietro Barbo's adoption of a spiritual career, after having been trained as a merchant, had been prompted by his maternal uncle's election as Pope Pope Eugene IV in 1431.

Barbo’s consequent promotion has been rapid; he had become a cardinal in 1440 and has gained popularity through his tenderhearted generosity.

He is elected Pope by the accessus in the first ballot, by a majority of fourteen of the nineteen cardinals in conclave on August 30, 1464, to succeed Pope Pius II.

Beforehand, in order to secure to the cardinals a greater share of power than they had enjoyed under Pius II, a capitulation had been subscribed by all except Ludovico Trevisan; it binds the future pope to continue the Turkish war, but he is not to journey outside Rome without the consent of a majority of the cardinals, nor to leave Italy without the consent of all.

The maximum number of cardinals is limited to twenty-four, and any new pope is to be limited to only one cardinal-nephew.

All creations of new cardinals and advancements to certain important benefices are to be made only with the consent of the College of Cardinals.

Upon taking office as Paul II, the Pope is to convene an ecumenical council within three years.

But these terms of subscription are modified by Paul II at his own discretion, and this action loses him the confidence of the College of Cardinals.

The justification for setting aside the capitulations, seen to be under way by the Duke of Milan's ambassador as early as September 21, lies in connecting any abridgment of the pope's absolute monarchy in the Papal States with a consequent abridgment of his sole authority in spiritual matters.

Almost from his coronation, Paul had withdrawn and become inaccessible: audiences are only granted at night; even good friends wait a fortnight to see him; his suspicious nature is widely attested.