The storyline for Ultima III is that twenty years after the death of Minax, (Relatively, since the entire conflict with Minax and her minions was fought across time and she was eventually confronted and defeated in the time of Legends.) trouble started anew in Sosaria when large numbers of evil creatures began again to harass the peaceful, prospering inhabitants of Lord British's kingdom. Then a fiery, unapproachable island rose mist-shrouded out of the ocean and rumors began circulating about a document found in Minax's empty castle that hinted at magical creature created by Mondain and Minax before Mondain's demise, and soon everybody retreated into the towns and the land was plunged once again into anarchy. You, of course, have come to set things right.