He acted as Venetian ambassador to both Ferdinand II, Holy Roman Emperor and Pope Urban VIII.
In light of the bubonic plague then decimating the city (it would claim 45,000 victims in all), Erizzo's election was not accompanied by the customary festivities.
Erizzo now ordered that Venice would celebrate the Feast of the Presentation of Mary (21 November) as the Festa della Madonna della Salute, where the city's officials parade from San Marco to the Salute in the sestiere Dorsoduro for a service in gratitude for deliverance from the plague.
In September 1644, the Knights of Malta captured a galleon of Turkish pilgrims bound for Mecca and then sought refuge in Candia (modern Heraklion) on Venetian-controlled Crete.
Erizzo began assembling a fleet to sail against the Turks, but, at age 78, his health failed him, and he died only one month after his military appointment, on 3 January 1646.