An underground movement on Romulus, encouraged by Ambassador Spock from 2368, that sought to reunite the Romulan people with their Vulcan cousins and eventually succeeded on the world renamed Ni'Var.
The movement is introduced in the two-part Next Generation story Unification. Picard and Data travel to Romulus in disguise to find Spock, who has gone there in secret to work with Romulans drawn to Vulcan philosophy. Senator Pardek betrays them, and Sela tries to use the cause as cover for an invasion of Vulcan.
Spock stays on Romulus to continue teaching, and the underground reappears in Face of the Enemy, in which Deanna Troi helps defectors escape aboard a warbird.
Discovery shows the outcome in Unification III. By the 32nd century Romulan survivors have settled on Vulcan, now called Ni'Var, and Burnham watches Spock's recorded words as she appeals to its leaders with the help of the Qowat Milat.