Phoenix-Fire War

The Phoenix-Fire War references a series of battles between the legendary Phoenix Etros and the Old Empire. Following the War of Suli Extermination, the settlers of the Old Empre began to spread all across southern Ferra. Eventually they reached the southern reaches of the Highlands. Here they began the first explorative ventures into the mountains, establishing small outposts and research posts.
One of these was constructed on a great volcano, aimed at studying its inherent magic and geological activity. During an experiment in 155 BtS, the researchers accidentally disturbed the nest of Etros who resided within the volcano. Etros raised up and destroyed the outpost, then returning to her nest. 
The Old Empire, hearing of the destruction and underestimating the phoenix's power, sent many smaller hunting parties to slay the beast. As more and more hunters arrived, and they began to corner Etros, she was agitated to the point where she launched out of the volcano and began to hunt down any sign of civilisation, be it Imperial or Lizardfolk.
This would lead to the destruction of most of the Highland outposts as Etros carved her way south. Eventually, she would be faced by a proper Imperial force at the Battle of the Phoenix Burns.