War of the Seven Kings
A continent wide war involving all of the Tanoine Kingdoms and Nohela, that left the Tanoine Kingdoms devastated. War had existed between the Tanoine Kingdoms (and was not an unusual occurrence, but the scale of this one was. The war lasted for 4 years, from 453 to 457. It started as Olewen Sulise and Towys tried to annex, Kheged. Lliannon and Nohela, honoured alliances and came to their defense. Galedein and Hianeth, sided with Towys, whilst Gahyn Beledhal, Rhian of Ihodel decided to take advantage of the conflict and attacked and annexed territory from both sides. The war was particularly devastating as Ys Luthiat sided with Towys, which a lot of Enchanters disagreed and chose their own sides. By the end of the war, Ys Luthiat had been destroyed and the surviving Enchanters created the Covenant of Alinniah to prevent Enchanters becoming involved in wars between nations. The war concluded with the end of House Sulise but the same geopolitical status quo from before the war. But all the nations were severely in a weakened state which left them open to an invasion from Johanna Martelis and the Velamanni.