The chief of the Turkish armed forces, Isik Kosaner, has resigned along with the army, navy and air force heads.It is very important to view these developments through the prism of the Muslim Brotherhood's 'Arab spring.' Turkey was home to the last Islamic Caliphate - the Ottoman Empire. The Muslim Brotherhood seeks to reestablish that empire; it's why the Brotherhood was founded. If Turkey's military falls to the Islamists, which becomes all but academic at this point, the Brotherhood has won yet another major victory in the region.
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.
There has been a history of tension between the secularist military and the governing AK party, with the two sides engaged in a war of words for the past two years over allegations that parts of the military had been plotting a coup.
Investigations into those allegations, known as the "Sledgehammer" conspiracy - appear to be the root cause of today's resignations, says the BBC's correspondent in Istanbul, with the senior military wanting to go ahead with scheduled annual promotions for some of the officers implicated - and the government refusing.
Here is a video report via GWP: