The article focuses on the manipulations of the genealogy of a legendarily famous Argive king or tyrant Pheidon ruling during the Greek Archaic Age (eighth to sixth century BC). The ancients did not possess any precise knowledge about his dating, which caused variable attempts to locate him in time. On the other hand, he became a target of different synchronisations which led to the manipulation not only of the Argive data, but also the genealogies of the Macedonian, the Median and the Assyrian kings. The discussion will reveal how genealogical evidence, or pseudo-evidence, was forged and manipulated for arriving at ostensibly historical accounts which, although possibly based on genuine traditions, produced visions of the past which in many points clearly did not correspond to the truth.