The Starfleet operation led by Admiral Jean-Luc Picard to move hundreds of millions of Romulans out of reach of their sun's coming supernova, abandoned after the attack on Mars in 2385.
The Romulan evacuation is the background to the first season of Picard, described in Remembrance and shown in flashbacks in later episodes such as Absolute Candor. When it became known that the Romulan sun would explode, the Romulans asked for help, and Picard gave up the Enterprise to lead the effort as an admiral, with Raffi Musiker as his aide.
The plan relied on a fleet of ten thousand transport ships under construction at the Utopia Planitia yards on Mars. Refugees were settled on worlds such as Vashti, where Picard worked with the Qowat Milat and befriended a boy named Elnor.
In 2385 rogue synthetic workers destroyed the shipyards and the fleet. The Federation, already under pressure from member worlds that objected to aiding an old enemy, cancelled the mission. Picard offered his resignation in protest and it was accepted. The supernova came in 2387.