Because the lion was traditionally considered the king of the beasts and the eagle the king of the birds, by the Middle Ages, the griffin was thought to be an especially powerful and majestic creature. Since classical antiquity, griffins were known for guarding treasures and priceless possessions.
In Greek and Roman texts, the earliest classical writings were derived from Aristeas (7th cent. BC)  Even though they are sharp-beaked, their being likened to "unbarking hounds of Zeus" has led to the speculation they were seen as wingless.