These are the eleven people who attempted to both prevent and cause the War Between the Crests. Obviously, they're not very good at what they do. Don't quit your day job.
Lavinia is the self-proclaimed leader of the Harbingers, though she is also the actual leader of the Underground Revolutionists. She has her right-hand man of Merritt Bethune and her left-hand man of Vash Moynihan.
To prevent a war between the Crests, while also giving the Lower Crests more recognition and prosperity.
Thieves, Militiamen, Spies, Weaponry, most of the Wards
With rumblings of a war starting, Lavinia sprung into action with Merritt and Vash. She quickly recruited the young chemist from Aerohaben (Cloyd Nipps) to assist in making bombs and other chemical warfare for the cause. When she learned of Zylphia's family in the area, she tried to recruit her, but she refused. However, she managed to convince her, if Iphigenia and Ezekiel were included. With much convincing from Iphigenia, Lavinia allowed the Harcourt twins entry and managed to snag the Great Captain Alethea Cheyne to join as well.
Laurentius is just an honorary member, though a lot of people don't acknowledge him at all.