Vorian Atreides' father, Agamemnon, claims to be over a millennia old. Although this isn't quite old enough to be the time of the Greeks back on the original Earth; however, he does refer to his family line to be descended from Atreus.
The original Agamemnon of Greek mythology was the son of Atreus. In greek mythology, Agamemnon and his brother Menelaus were referred to as the Atreides, hence the House Atreides, home to Paul, Vorian, Leto, and many others in this family line.
Was Agamemnon really the original king from Greek mythology, or was he merely another descendant in Atreus' family line?
It seems seems impossible that Agamemnon could have been converted into a cymek, as it turns out, ancient Greek technology was not known to have the ability to sustain human brains independently of the body.