The Old Empires are the empires of Lost Samarkh, Ketesh, and Rur, three ancient kingdoms that predated the Age of Chaos and coexisted with the last empires of the Elves. Humanity as a species first rose out of barbarism to invent writing and technology and law under the rule of these kingdoms.
The fall of the Starstone destroyed Lost Samarkh and formed the Sea of Horses. [[Ketesh[[ and Rur suddenly found their territory transformed from verdant cropland to the Burning Sands, and did not last more than a century past the fall of Samarkh.
Explorers constantly claim to discover new ruins that supposedly date back to the Old Empires all the time. The truth of these claims cannot always be verified.