The Demon Wars

The Demon Wars were a series of conflicts following the invasion of an enormous host of demons into Tyrrus. The conflicts mostly took place in the northern regions, however many major cities were involved in fighting back against the scourge, including New Haven, Dunberlaine, Telmont and Kilzig.
The Demon Wars officially begun in 20.35, when the demon horde crossed the passages of Glaugan and begun laying waste to the Highlands. The conflicts were not considered to be "over" until 20.60, when it seemed the horde had been entirely wiped out, or were at least no longer constantly on the attack.
The cause of the Demon Wars is unknown. Some believe the horde had been summoned by Hirokiri Shamans, others believed it was a plot of Azjol the Spider King, or Mallobyrne the Fomorraigh Lord, in an attempt to reconquer Tyrrus. The most extreme doomsayers stated that it was divine punishment from the gods, for the hubris of mankind.
The Demon Wars resulted in the accelerated military development of New Haven, and caused them to rely more heavily on their Arcane dragon allies.
The Demonic armies were repelled largely due to the aid of the Light priests of Sollan Temple and Neo-Izero.