The chief of the Turkish armed forces, Isik Kosaner, has resigned along with the army, navy and air force heads.
They were furious about the arrest of senior officers, accused of plotting, shortly before a round of military promotions.
A series of meetings between Gen Kosaner and PM Recep Tayyip Erdogan failed to resolve their differences.
Turkish President Abdullah Gul moved quickly to appoint General Necdet Ozel as the new army chief.
Gen Ozel is widely expected to be swiftly elevated to chief of the general staff in place of General Kosaner. Tradition dictates that only the head of the army can take over the top job.