The Empire was brought together when an outside figure like Alexander the Great united the squabbling "Greeks" against the "Persians," both of which were skilled in the magical arts. The "Greeks," however, prevailed as the "Persian" empire suffered from discord within - and numerous enemies without - who were only too ready to attack. It split into several successor states. Meanwhile, the "Byzantine" Empire rose to prominence, slowly subjugating client states and outright conquering lands around it to nearly encircle a great inland sea. Magic arts flourished, reaching a peak that has not been seen since.
But let us call the Greeks Darians, and refer to the Palantyne Empire rather than the Byzantine. Persia is mighty Zantiph. For a thousand years the Empire endured, through its powerful Colleges of Sorcery; by an efficient bureaucracy that managed state affairs even during the reign of incompetent Emperors; and through highly-trained and loyal legions. But pieces slowly whittled away, as the fate of the long-defeated Zantiphan Empire caught up with them. Internal politics and power struggles weakened the Imperial Court from within, while humanoid and barbarian tribes took the opportunity to take what they could from the borderlands. Frontiers were conquered. Provinces rebelled. Others remain part of the Empire in name only, but govern themselves, as the Darian city-states now do. As a final blow, the Zantiphan successor states are united again.
With new vigor and purpose, the Padishah who now sits on its Lazulite Throne presses every advantage against his ancient enemy, Palantys, the jeweled center of the World, and tests the mettle of her Dragon Legions only sparingly. Atop Mount Pergion, in the City itself, nobles intrigue against each other and the Emperor, and decadence abounds. Meanwhile, the sun-worshiping Helic Cults have risen to prominence, preaching a return to Law under their Hierarch. In their sylvan realms, the Elves appear unmoved by human affairs, having predicted the decline of young Palantys, as they foretold the first fall of Zantiph before it. North, across the Cerulean Sea, a "barbarian" kingdom in the old province of Esclamor (Hiskalaborea), has absorbed aspects of Palantyne civilization into its feudal order, and welcomed the Helic religion. Dwarven kingdoms once traded with the Empire, but have become more secluded since the humanoid invasions of the past two centuries. In corners of the Old Empire, ruins attest to the power of long-dead Palantyne wizards, and earlier sorcery that even they could not attain.
The young kingdom of Esclamor is the setting for initial adventures, on the borderlands where the King's cousin, Lord Thrandon, led a campaign against humanoid armies several years ago. Interestingly, the human realm was aided by forces from the nearby Elven domain of the Idyllglades, as well as the Hill Dwarfs of Ironcrag, an alliance not seen in recent memory. While the threat was mostly quelled, pools of evil remain, ready to rise again at the next opportunity. Into this milieu enter the characters, who have heard of long-lost treasures and lore and are ready to make their names.