(Capcom's primary storyline)
When the Federal Bioterrorism Commission head, Commissioner Morgan Lansdale, began masterminding a conspiracy to increase his powers as commissioner of the FBC, Il Veltro, a group of men with extremist beliefs, were funded by the Commissioner into becoming an armed bioterrorist faction.
Just five days into the attack, Lansdale killed off the Veltro agents on the first two ships, which were to be used later as private research institutes under the overall command of Lansdale by immediately releasing the B.O.W.s stored on the ships. When one of the Veltro agents, Jack Norman, began to suspect Morgan's involvement in the incident, Lansdale activated the ship's self-destruct system. The Dido and those onboard sank to the bottom of the Mediterannean Sea.
In 2005, Jill Valentine and Chris Redfield explored the submerged Queen Dido in order to prove Commissioner Lansdale's involvement in the Terragrigia Panic. While infiltrating the ship, they found the corpses of several Globsters, which were once Veltro agents. Jill discovered a locked blast door which lead them to a section of the ship that wasn't flooded. There, they found the corpse of FBC agent Dario Barioni, along with a video tape in which the former stated that his whole team was killed by "the devil himself", and that their mission to retrieve the video log (which contained evidence of Lansdale's collaboration with Veltro) had failed.
Thus, Jill and Chris ventured further into the sunken ship, crossing the dining room, where a memorial to the fallen Veltro agents had been built by Jack Norman, the only surviving member of Il Veltro. They found Norman within the ship's throne room, where they fought him in order to retrieve the video log. After they succeeded, they escaped, leaving Jack Norman's mutated body and the sunken ship behind.
It is unknown what happened to Queen Dido afterwards.