Allegra had tried compromise and all she had to show for her work was a crater in the side of a mountain. She had tried peace, and that just made the rebellion worse. She had seen a demon with her very eyes, and that hadn't been enough to move the cardinals into action. But despite all this, never had she thought they would try to murder her.
When General Bonacieux shows up at the Cathedral to demand she be turned over for public execution, the cardinals waver. Instead of submitting, Allegra declares her own war: freedom for all mages.
As new demon marks open on Orsini soil, Allegra takes a stand against the very people who gave her power. For as Captain Stanton Rainier said, they would only get her over his dead body.
So much for peace.