The Guardians of Night began as a special sect of Knights Academic formed by Vox Verlix while he still controlled New Sanctaphrax. Unlike the Librarians, the Guardians believed that the cure for Stone-Sickness would be the sacred lightning of a Great Storm, and they despised the Librarians for their belief that a cure lay in the Deepwoods. As tensions between the Guardians and Librarians worsened, Vox constructed the Tower of Night on the New Sanctaphrax rock, setting aside the upper levels for the Guardians and the lower levels for the Librarians.
Soon, however, a leader rose from the Guardians' ranks, by the name of Orbix Xaxis. During the Guardians' uprising on what came to be known as the Night of the Gloamglozers, he and his followers cast Vox and the Librarians out of New Sanctaphrax and the Guardians seized the entire Tower of Night for themselves. For a while, an uneasy peace formed between the Guardians and Librarians, with the Guardians keeping to themselves in New Sanctaphrax and the Librarians conducting their work in a palace in Undertown. Later on, though, the Guardians launched a massive attack, and the Librarians fled to the sewers. The Guardians coexisted in reasonable peace with General Tytugg's goblin armies, because the Goblins enslaved the Undertowners to work on the Sanctaphrax Forest.
The Guardians of Night wore black cloaks emblazoned with the white symbol of a screaming Gloamglozer's head on their chests. Most of the Guardians remained holed up in the Tower of Night, performing complex and twisted rituals to prepare for the arrival of a sacred storm. The Guardians also spent a lot of their time attempting to capture Librarians for interrogation and use in Orbix Xaxis's twisted "ceremony"--placing them in the Ceremonial Cage and sacrificing them to the Rock-Demons.
The Librarians launched a first attack on the Tower of Night, but were defeated. In The Last of the Sky Pirates, a second attack followed, in which the Guardians of Night suffered severe losses and their prisoner, Cowlquape Pentephraxis, was freed.
During the events of Vox, all of the Guardians of Night were killed when the Tower of Night was destroyed by a colossal lightning bolt from Vox Verlix's Dark Maelstrom. The sole survivor among the Guradians was Xanth Filatine, who survived because he was not at the Tower of Night when it was struck.