With its white granite rocks and turquoise waters, the island, the second largest in the Pontine archipelago, has a long history as a place of punishment and torture for the exiled and outcast.
Known in Roman times as Pandataria, it was first famed for housing emperor Augustus's daughter Julia the Elder after she was charged with adultery, before emperor Nero exiled his wife Octavia here.
On a nearby, rocky outcrop called Santo Stefano, the Bourbons built a horse-shoe shaped prison in 1797, made up of 99 cells set around a circular watchtower, with room for over 600 prisoners.
It was used by the fascist regime during the Second World War as a place to which to banish political dissidents, with some 2,000 inmates languishing on Ventotene, by then dubbed the “island of confinement”.
Santo Stefano prison. Photo: John Worth/Flickr
Among them was Altiero Spinelli, a journalist and communist activist, who was sentenced in 1927 to 16 years in prison for his writings criticising the rise to power of Benito Mussolini.
Transferred to the island in 1941, it was during his detention here that he secretly drew up with fellow prisoner Ernesto Rossi the “Ventotene Manifesto”, one of the founding texts of European federalism.
The brigand, the president
Written on sheets of cigarette paper and hidden in a tin box with a double bottom, the manifesto “for a free and united Europe” was smuggled to the continent by Ursula Hirschmann, a German anti-fascist activist, and circulated among the Italian resistance.
The idea was to create a federation of European states which would tie the countries of Europe and prevent future wars between them.
Spinelli asked to be buried on the island, and Italy's Prime Minister Matteo Renzi, German Chancellor Angela Merkel and French President Francois Hollande will lay flowers on his grave on Monday.
Renzi picked the symbolic site for the crisis talks on the European project's future “to pay homage to what happened during what was perhaps the most difficult moment in the history of European identity”.
The island was taken back under Allied control in 1943 under the cover of darkness by a small unit of American troops which tricked the stationed German garrison into surrendering without a shot fired.
The volcanic rocks, sandy beaches and underwater grottos of Ventotene are now peopled with tourists and scuba diving fanatics rather than outcast Roman women or anti-fascists.
Unused since 1965, its dilapidated jail – once home to such illustrious inmates as the brigand Carmine Crocco and the future president of Italy Sandro Pertini – has fallen slowly into ruin.
In February, Renzi announced an 80-million-euro ($90-million) plan to restore it and turn the abandoned lockup into a museum and academy for the EU's elite.