Conjunction of the Spheres

The Conjunction of the Spheres is a cataclysm which occurred 1,500 before the events in the novels, trapping in the this dimension many "unnatural" creatures, including ghouls, graveirs and vampires. It was during this that the elves say humans first appeared, their own world having been destroyed. Humans did not settle on the continent many hundreds of years after that.

Note
In Blood of Elves, Danusia Stok translates "conjunction" as "interpenetration".

There is also a book in the game by the same title.

Source

 * The Conjunction of the Spheres

Konjunkce sfér Sphärenkonjunktion Conjunción de las Esferas Conjonction des sphères A Gömbök Együttállása La Congiunzione delle Sfere Koniunkcja Sfer Сопряжение Сфер