Swords of the Eastsea is, to paraphrase Barbara Tuchman, the Early Modern Age of Europe seen through a distant mirror. Imagine that there’s a longer history than there is: stories of great heroics, an enemy foul beyond belief, swarms of dragons that once blotted out the sky, the dead walking the earth, a gilded empire founded by men from beyond the seas. And then it was gone, as the age of myth passed and the great deeds were all done and the Old Enemy was defeated. The great faiths of our world arose and all were gone with the Black Death that was far more severe than the Black Death was in our world.
Some of that old age still lingers out in the borderlands: Dwarven holds where dwarves still keep to their own ways, Elven refuges in the deep green woods. Orcs stalk the frontiers, dragons still slumber in the Scandian mountains. There’s wizards who can fly and wizards who can change into animals.
Meanwhile, great galleons explore the oceans of the world, vast armies outfitted with pike and musket march onto the battlefields of Germany as the Swedish Empire makes its bid for dominating the Eastsea. Merchant-adventurers travel everywhere, artists are creating books and sculpture and paintings. The old, medieval age is dead and the Old Empire of the Sacred Kings has been in ruins for two thousand years. It’s the Great Age.