Museum of the Roman Ships historical timeline

Last updated on October 8, 2026

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1st century A.D. Two ships are built on Lake Nemi under Caligula -- the larger 73 m long with a 24 m beam, the other 70 m by 20 -- the larger an elaborate floating palace with marble, mosaic floors, heating, plumbing and baths. Roman law forbids any vessel on the lake because it is sacred, which implies a religious exemption; Caligula supports the cult of Diana Nemorensis whose temple stands beside the water.
1446 Cardinal Prospero Colonna and Leon Battista Alberti locate the wrecks at 18.3 m, too deep to salvage, and damage them pulling planks away with hooked ropes. Alberti establishes little more than the type of wood and its lead sheathing.
1535 Francesco De Marchi dives on a wreck in a diving helmet and recovers bricks, marble paving, bronze, copper, lead and timber, showing that the hulls used mortise-and-tenon joinery. No academic interest follows and the objects recovered are lost.
1895 Recovery of individual original pieces from the lake begins, and continues until 1932. These are the only parts of the ships that will survive the next fifty years.
1929 Both ships are raised from the lake bed, and a museum is built on the shore to hold them.
1944 On the night of 31 May the museum burns. A German battery had set up 150 m away on 28 May and driven out the custodians; US shells struck the building around 8pm and flames were seen two hours later. The Germans left on 3 June and the returning caretakers found the ships reduced to ashes. In July an Italian-American commission reports the fire as "most likely" a deliberate German act.
1995 The Association Dianae Lacus is founded and begins Project Diana, a full-size replica of the first ship built to deck level only, since nothing records the shape of the buildings that stood on the deck.
1998 On 18 July Nemi's town council votes to fund the forward section, and work starts at the Torre del Greco shipyards.
2001 The forward section is completed and transported to the museum, where the rest of the vessel is to be built. The estimated final cost is 7.2 million euro.
2011 After a sponsorship announcement in November 2003 and no press release since 2004, the association's website is deleted on 1 October. The replica is still a bow.
2023 Flavio Altamura and Stefano Paolucci publish a review of the 1944 investigation using unpublished documentation and modern fire-investigation methods, and conclude that the only plausible cause was the Allied artillery that holed the roof -- impacts the commission excluded at the outset, against the view of the only artillery expert among the investigators.

Verified against Wikipedia, October 2026.

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Checked against Wikipedia — The Nemi ships were two ships of different sizes built under Caligula in the 1st century AD on Lake Nemi, the larger an elaborate floating palace containing marble, mosaic floors, heating and plumbing and amenities such as baths; the larger was 73 m long with a beam of 24 m and the other 70 m long with a beam of 20 m, As the lake was sacred, no ship could sail on it under Roman law, implying a religious exemption; Caligula particularly favoured the Egyptian Isis cult he had established in Rome and also supported that of Diana Nemorensis, and the ruins of an ancient temple dedicated to Diana are located at Nemi, In 1446 Cardinal Prospero Colonna and Leon Battista Alberti discovered the remains at 18.3 metres, too deep for effective salvage, and damaged the ships using ropes with hooks to tear planks from them, Alberti learning little more than the type of wood and that it was covered in lead sheathing; in 1535 Francesco De Marchi dived on the wreck using a diving helmet and found bricks, marble paving stones, bronze, copper and lead artefacts and timber beams, adding the knowledge that mortise and tenon joints had been used, Original individual pieces from the Nemi ships were recovered from Lake Nemi between 1895 and 1932, The ships were recovered from the lake bed in 1929 and were destroyed by fire in 1944 during World War II, The ships were destroyed by fire on the night of 31 May 1944; on 28 May a German artillery unit set up a four-gun battery 150 metres from the museum and drove out the custodians, the German presence attracted Allied counter-battery fire, several United States Army shells hit the museum around 8pm and significant flames were observed about two hours later, and when the caretakers returned after the German forces left on 3 June they found the ships reduced to ashes, The official report submitted in July 1944 characterised the fire as "most likely" a deliberate act by German soldiers and that narrative was widely accepted and recognised officially, while the head of the German Kunstschutz office suggested American artillery fire; a 2023 study by Flavio Altamura and Stefano Paolucci reviewed the 1944 investigations using unpublished documentation and modern fire investigation techniques and concluded that the only plausible explanation is impacts from Allied artillery shells, at least four of which accidentally struck the museum and holed its roof on the evening of the fire, and that the commission arbitrarily excluded those explosions from the earliest stages of the inquiry against the opinion of the sole artillery expert among the investigators, Photographs, the drawings made for the Italian Navy survey and those made by the archaeologist G. Gatti survived, allowing reconstructions to be made; the Association Dianae Lacus was founded in 1995 and initiated Project Diana, a full-size replica of the prima nave to be constructed to deck level only since no record is known of the shape and size of the buildings and temples built on the deck, with the town council of Nemi voting on 18 July 1998 to fund the forward section, which was completed in 2001 at the Torre del Greco shipyards and transported to the Nemi museum at an estimated final cost of 7.2 million euro; Assimpresa announced sponsorship of all required timber on 15 November 2003, no press releases have been made since 2004 and the association's website was deleted on 1 October 2011 (October 2026).

Museum of the Roman Ships historical timeline

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