He initially took the political career in the Republic of Venice, but already in 1624 moved to Rome and became an ecclesiastic: on 28 September 1626 he was ordained priest.

In Ceneda he succeeded to keep exempt the town from the taxation over the near Treviso,[2] and in 1634 he issued a ban prohibiting the insults to the Jews during the processions.

[2] A few months after the Papal conclave, 1655, he resigned as bishop of Vicenza in order to stay in Rome to support the politic of the Republic of Venice, of which he always remained a loyal servant.

In particular during the Fifth Ottoman-Venetian War he persuaded the Pope to exhort various Western European nations to send men, ships and supplies to defend Crete.

In exchange to this effort the Pope requested and obtained, due to mediation of Bragadin, the re-admission in 1657 of the Jesuits in Venice[2] from where they had been expelled in 1606 for effect of the Venetian Interdict.