I'm in the process of building a world for a D&D 5th ed campaign which is due to kick off in the new year and I'm looking for some feedback on a time line, political climate, etc. for the world history. This is a fantasy setting. Magic is a big part but not hand wavy.
800 Years before the story starts on a large land mass similar to the map of the Mediterranean used in the Total War games series. There were 8 major cities each which housed a major school of magic. Gunpowder had just started to be used. Steam and electricity were experimental but not yet viable.
A portal to another dimension opens at each College destroying the surrounding city. Rulers, Garrison, libraries, industry and citizenry all wiped out. Massive fire, explosions, daemons running through the streets destroying and slaughtering.
200 Years of war. Other worldly entities driven back or slain. As a final act the other world invaders detonate the portals and wipe out the forces fighting them —armies, generals, kings, lords, etc all dead. Country side is ravaged.
Next we have about 500 years of power grabs, small wars, disease, death, more destruction of history, libraries, colleges, industry etc.
Followed by a 200 year period which sees the rise of city states and the formation of a loose arrangement of alliances. Some city states are run by Kings, Emperors, elected councils, elders, religious organisations, trade guilds, Knightly Orders, criminal groups, militias, warlords, scholarly groups etc.
Apart from a few minor conflicts between factions that flare up from time to time the land has settled into an uneasy peace. Rebuilding is well underway.
Adventure starts in small trading port with an adventurers guild run by a council made up of representative of the major organisations in the town the merchants guild, the ship builders guild, Militia chief, explorers guild, etc.
When the infighting between the various factions breaks out into all out war our band of adventures get swept up in it completing missions for various factions and changing the course of the war.
Does this sound plausible. Suggestions to make it more so appreciated.