[3] In 1618 Marco Gradenigo was elected provveditore alle Pompe (a minor public office, aimed to limit the use of precious and luxury objects and their display).

Other minors public offices were assigned to him up to 1624 when he became member of the Avogadoria de Comùn (similar to that of a modern State Attorney), and in 1626 he was appointed Superintendent of the Fortresses.

[3] Arrived in Candia in February 1628 Marco Gradenigo, with his resolute character, tackled head-on the main problem plaguing the city, i.e. the abuses of the local Venetian nobility against the Greek urban and rural population.

In the capital Candia he supported the urban development, applied a tax exemption to foreigners intending to trade and ordered the first census of the population.

[3] Thanks to the support of his influent father, on 22 September 1629 Marco was chosen as coadjutor bishop with right of succession by his distant relative Agostino Gradenigo, Patriarch of Aquileia.