An ambitious woman, she was able to persuade her husband to exclude his sons by his former marriage from the throne; instead it would go to Etazeta's children. Since these were still very young the king thought to strengthen the throne by offering the guardianship of the infants to the sovereigns Ptolemy II of Egypt and Antigonus II of Macedonia; also the city-states of Byzantium, Heraclea and Cius were added to the guardianship.
At the death of Nicomedes I around 255 BC, she ruled on behalf of her infant sons. However, Nicomedes' first-born, Ziaelas, refused to accept his father's decision and started a war against the stepmother to conquer the kingdom. Etazeta tried to resist, also marrying herself with the former king's brother, but at the end, about 254 BC she was evicted by Ziaelas and forced to flee to Macedon with her sons.