The cathedral in question is an unholy structure located in The Westlands, not far from the border of Sefonia.

In 609, forces of evil from Quayern or perhaps Ossau constructed a small chapel outside the nearby village of Trevisi. The chapel was then-- with surprising speed-- built into a stone cathedral from which bandits and monsters began to operate with increasing frequency.

In 614, a combined force was sent to destroy the Cathedral, and put an end to the marauding. This allied army clashed with a horde of evil men and monsters at The Battle of Westmarch.

Men-at-arms from Sefonia and Quayern united with trolls, rangers, and a platoon of archers borrowed from Sefonia's navy to face the threat of the Horde of Elemental Evil, consisting largely of monsters. The arrival of the Horse Clan of nomads turned the tide of battle, backing the Horde up against the edge of Lake Murkness, where the Horde was routed and slaughtered.

At some point in this battle, Cidric, a commander-general of the Dragon Knights, and member of The Six, was slain. The League of Black Swords was notable in their absence at this pivotal moment in the history of the Westlands, and their failure to take part in the Battle of Westmarch contributed to the group's decline and eventual disbandment.

After dispersing the Horde of Elemental Evil, the allied forces laid siege to the Cathedral of Elemental Evil itself, defeating those within it within a fortnight. Spellcasters loyal to the goodly army cooperated on a spell of sealing that bound a marid (a major instigator in the Horde of Elemental Evil) to some of the deepest chambers in the Cathedral's dungeons.

The site itself remained, however, and over the following decade rumors of evil presence there persisted. The Viscount of Rhastani and the warlock Julian became increasingly concerned, and cooperated to build a large castle next to the village of Trevisi, and a large wall around it, to guard against the possibility of the Cathedral rising again.

For the next five years, Trevisi gained in wealth thanks to adventurers who came to the area seeking out remnants of evil to slay. Things quieted down for another four years as the area returned to peace and normalcy, but in 619, evil began to stir again, with groups of bandits riding the roads. In 620, things get worse...
This message was last edited by the GM at 21:09, Sun 22 Nov 2020.