Ancient Ones

The Ancient Ones are credited with being the oldest race in the Green Isles though none exist in the present time. They were an advanced civilization, which using intellect, created the Cliffs of Logic, as a test to those worthy enough to master the riddles chiseled onto its face.

Much is still unknown about the Ancient Ones. Scholars of the Winged Ones painstakingly sift through the few documents they have obtained to learn more of this race from which they believe they may have come. It is believed that Ancient Ones achieved flight without wings. They may also be the race that once inhabited the Underground Realm of the Gnomes, of which Prophet Hector, and the Aged One were once members.

They may even be tied to the ancient race that once inhabited the area that became the Endless Desert of Serenia. Their use of technology lead to the destruction of their cities creating the desert. The ruins of one of their temples still stands on the northern edge of the continent.

Ancients in the unofficial games
The Ancients tie into the plot of King's Quest II: Romancing the Stone. The Ancients then known as the First Mages, were a race of powerful magicians. Legenimor, the First King, lead the arrival of their kind from another world (perhaps the stars) and founded Daventry. They both magic and civility to the kingdom and the surrounding lands. Legenimor soon became the most powerful ruler the world had ever known. However soon terrible war broke out, the Grand War, and many people died. Legenimor blamed himself, and commited his power to the stars. Legenimor's brother Morgelein disappeared during the war. He later became The Father, and began preparing for an upcoming Acension, and regaining his brother's power was an important part of that plan. He hoped to surpass his brother, becoming the most powerful ruler the world had ever known since the days of the Ancients.

All of the decendents of the First Mages, were mages themselves. Count Caldaur is one of the mage decendents.

Real world
The concept of a mysterious extinct highly advanced civilization that left mysterious ruins and mechanisms behind is extremely common in science fiction, fantasy and folklore.