Gaerlan was the younger brother of Delacim, the pupil of Asheron. He sat in on many of Asheron's classes and learned magic that way (though he never was very adept at it). He later learned the truth of Asheron's longevity and told the Emperor Kellin II who used it as leverage to control Asheron with the threat of turning him over to the Nali otherwise. When Delacim was slain during a trip to the Olthoi homeworld, Gaerlan placed the blame solely upon Asheron and sought vengeance against thim thereafter.

Gaerlan escaped Auberean into portal space along with the Emperor as part of Asheron's sundering spell. He was later freed from portal space as a side effect of Martine's creation of the portal routes to Marae Lassel.

His first known appearance was in Leafcull PY12 (The Gathering Storm) though it was much later before he actually revealed himself.

He quickly worked his way into working with both Nuhmudira and Martine. He brought men suitable for Nuhmudira's "wishes" and made a bargain with Martine: he agreed to find Asheron in exchange for something only Martine could do. This is probably related to the raising of Gaerlan's citadel but is never clarified.

Gaerlan later assisted Martine in the destruction of six of the Nexus towns.

He began experimenting with the creation of new creatures including Crystal Golems and later the dual-elementals, first seen within Martine's Quiddity Ingot dungeons.

Only later was the full truth of Gaerlan's goals learned. Though long ago he realized that Asheron was a heretic against the Northern Church he ceased to care. Gaerlan hated his own people and their hypocracy. Some time before the sundering, he stumbled across an ancient Gelidite Library in northern Osteth -- the home of the purged Disciples of the Blood. He used their magics to control elementals and unearthed their old cisterns (the propylaea). He saw this elemental magic as a way in which he could gain vengeance upon Asheron for the death of Delacim.

Using the Disciples magic he created the first Acid and Frost elementals within the cisterns (something the Disciples themselves were afraid to do). He also expanded the numbers of Fire and Lightning elementals. But his initial work within the Propylaea was halted by the olthoi invasion and the sundering.

Upon his return, he took up where he left off. This was the reason he manipulated Nuhmudira and Martine. Secretly he loathed Nuhmudira as he saw her carrying out blasphemous Falatacot style magics. He captured her within the Gelidite Library, forcing her to face the judgment of her own people for what she had done (though he had future plans for Nuhmudira himself).

When Asheron and Elysa met Isparans at the festival stones during Seedsow PY13 (Castling), they were disturbed by Martine who heavily injured Asheron. It was at this time that Gaerlan's citadel first appeared and he came into his own power. He confronted Martine, telling him that he would not be the one to kill Asheron, that was for Gaerlan himself. But before he could, the Isparans attacked and bought time for Asheron to escape. It finally was clear that Gaerlan was the mysterious "apprentice" of Martine.

Retreating to his citadel, Gaerlan continued in his plan: to bring fourth four elemental generals: Stasis, Strife, Corrosion, and Tempest; and then to take them to the Elemental Hall (located beneath Yanshi) and use them to summon the Harbinger. He planned to have Nuhmudira serve as the vessel of the Harbinger. In that way he could control it and use it to destroy Asheron.

But his plans were foiled because the Isparans voted against all odds to save Nuhmudira. She escaped and Gaerlan found himself without a vessel. Even so, he continued in his summoning spell though without a vessel there could be no control and the Harbinger would run amok. But his final summoning failed, the after effects ruing the town of Yanshi above.

Martine taught the Isparan people how to weaken Gaerlan's citadel. This allowed Martine to confront Gaerlan atop the citadel. Initially Gaerlan was winning but Asheron appeared to help. Not before Martine was imprisoned within an elemental prison. But Martine used Virindi magic to escape the prison and toppled the citadel.

For a time Gaerlan disappeared from view. But then he reappeared within his shattered citadel where we he was finally confronted by Isparans and defeated. Nuhmudria appeared before him and converted him into an undead creature stuck forever in a phylactry for Isparans to train on.

But despite being defeated the Harbinger was born beneath Yanshi. Elysa led an initial attack that was repulsed, but later Isparan attacks succeed in defeating it. Thus ended the vengeful schemes of Gaerlan.