After the 1669 Venetian surrender of Candia in Crete to the Ottomans, Corfu became the last Venetian possession and bastion in the Levante. Consequently, the Venetians redoubled their efforts at strengthening the defences of the island. In 1671 a Venetian official by the name of Dona was sent to evaluate the defences of Corfu and submit a plan to the Venetian Senate.