The mighty Linaean (Lin-ay-en) Empire united much of the known world under a single stony fist wreathed in fire.
The Imperial Family were mages, so that’s pretty literal. Emperor Nintarus the Unsubtle was particularly fond of the Burning Fist of Stone.
Their talent with Elemental magic let them unite a kingdom around the city-state of Linaea. Starting with Bedonna the Blizzard, they expanded their hold generation after generation, conquering neighboring human, teifling and dragonborn states, then making the local nobility citizens in the growing empire.
They (mostly Exortia the Bloody) overwhelmed the hill dwarf and sylvan elf lands in the north, then turned their eyes to the Eladrin mage-king who held the Crossing. He was no match for the full might of the Empire and (under Pidarius the Earthrender) they brought the eladrin, halfings, and orcs to the south to heel. Sentients of all races were tolerated in their borders, although only a select few of any race were truly classed as citizens. Any religion or culture was permitted, so long as they didn’t foment rebellion.
In the end, the Empire rotted from within as a succession of fools and weaklings took the throne (Postius the Credulous and Ustus the Gormless were particularly damning). And then at last, during the reign of Milnia the Dour, the Vadri Horde swept over the plains where Linaea stood, and wiped the last vestige of the Empire from the map.