"Centuries ago a thriving kingdom refused to abandon it's deities when a powerful deity wanted to expand it's dominion. As a result of their insolence, the false gods were banished and the kingdom shattered to tiny islands."
Sea routes between ports are clarified by darker blue lines.
Get it from here:
I personally won't link to Dominions 3 content made by me any more and I hope no-one else will either (old links are fine, whatever). You should be able to find them or most of them by asking on IRC or googling the other forums
EDIT: By the looks of it I tagged it as MP instead of Map. Oh well.