The Venetians, at the suggestion of Sofianos Eudemonogiannis , a Monemvasite soldier in the service of Venice, began to build it in 1579 and completed it in 1584 to strengthen the protection of the island against the Turks.In 1588 the fortress was destroyed by lightning that struck the gunpowder depot (with 350 barrels of explosives). It then had 24 cannons, 3398 missiles and 40,000 pounds of gunpowder, and was supplied by 2 wells and 5 cisterns.

The Venetians rebuilt it in 1630.

After the conquest of Crete by the Turks in 1669 the Venetians kept its three small islands, Gramvousa, Souda and Spinalonga and organized them as best they could.

They kept his ownership for another 23 years, until 1692, when the Turks finally managed to understand it, bribing the Venetian commander who with the surrender he took lived happily for the rest of his life in Constantinople. In fact, in his time, he was known throughout the city as “Captain Gramvousa”.