From the publisher (back cover):
All for one, and one for all
From 1550 to 1650, Europe was torn apart by constant warfare. Social order collapsed under countless religious and civil wars. This was the age of Elizabeth, Francis Drake, Cromwell, Richelieu, D'artagnan and Captain Blood. Bold mercenaries carved kingdoms out of the chaos; inquisitions and witch hunts raged; brazen pirates plundered the Spanish Main. A Mighty Fortress blends the AD&D game with this swashbuckling era. Flourish a rapier, shoulder a musket, and step into the golden age of adventure!