abstract:Deioces, Diako, Deyaco, Diyako or Deiokes (Greek Δηιόκης) was the first king of the Medes according to Herodotus. In the late 8th century BC there was a Daiukku or DayukkuCuneiform Da-a-a-uk-ku; this, like the Greek form, presumably reflects an Iranian *Dahyu-ka-, based on dahyu- 'land': Rüdiger Schmitt, "Deioces," Encyclopaedia Iranica.