The elven civil war is the most recent conflict shaking Cerulen. It forced the now so-called High Elves to flee on (and with) their floating islands.
The Elves were once one major race, living in harmony with nature. They always were proficient in arcane as well as natural magic. The ones preferring arcane magic slowly shifted to living in more traditional cities, just like the other races. In time they were building few, but huge cities, that in the eyes of the Wood Elves seemed to stain nature itself. Tensions arised, which were usually handled peacefully. But at some point the Wood Elves had enough, suddenly attacking the now called High Elves.
By defeating the High Elves they forced them to leave the country. In the last moment the High Elves decided to use the newfound floating crystals to flee with their most important cities. Many High Elves fled to other cities and countries like The United Kingdoms .
Huge gaps in Wood Elf land where cities once stood, thanks to the floating crystals of the High Elfs. They don't mind too much, since their cities are integrated in the forest and no more cities stain the landscape. The High Elves now live on cities floating over the rest of Terim, slowly scattering across all continents. It forced the High Elves to develop more technologies, traditional and magical alike. It is what made Enania Valgeiros develop floating crystals. The general Elven population dwindles dramatically, not to a point of concern, but it is still noticable.
Floating Crystals, Mage Carriage