"Dates for the Mermnad kings are uncertain and are based on a computation by J. B. Bury and Russell Meiggs (1975) who estimated c.687–c.652 BC for the reign of Gyges. Herodotus gave reign lengths for Gyges´ successors: Ardys for 49 years (to c.603 BC); and Sadyattes for 12 years (to c.591 BC)." - (en.wikipedia.org 17.11.2019)
en