Shortly after their arrival in the Valley, the Children of the Flame used their superior weapons and military tactics to soundly defeat the Vangesh hordes and drive them back over the plains and through the Eastern Pass. Carved out of the rock of the Eastern Mountains immediately after the Vangesh retreat, the Barrier Fortress was designed and constructed to guard the Eastern Pass against further waves of eastern marauders. Despite centuries of siege, the massive walls and giant gates of the stronghold proved impregnable.

The peace of past several centuries has transformed the Barrier from a military center to a bustling cosmopolitan city. Relations with the Vangesh have improved dramatically in this time, as evidenced by the substantial Vangesh presence in the city as craftsmen and traders of exotic wares. One of the first projects undertaken by the Children after the arrival, the Barrier Fortress stands today as one the oldest modern structures in the Valley and an impressive testament to the Children's military and architectural genius.