Freeholm begins rapid trade expansion southward. Other civilizations interact with airships. Reasonably safe travel between islands first available. Freeholm & Buram begin to outpace other civilizations in terms of wealth and technology.
With air travel more accessible, the Southern Countries all vie for opportunities to trade, develop fleets, and spread culture and trade. Educated citizens begin to have rudimentary knowledge of other nations' cultures and traditions.
Koryo ships begin invading Southern countries with a rapid Blitzkrieg-style strike. Freeholm and Buram are quickly hit and overtaken. Southern Countries band together at Samui to repel Koryo advanced forces. Southern countries able to fend off invasion, but take heavy losses.
War against the Koryo continues raging. Various factions resist Koryo occupation and conquest with varying results.