The detention of Ilker Basbug is the main talking point in Turkey.
Newspapers heralded the arrest on their front pages. Some detailed the accusations that he was the leader of terrorist organisation and had been preparing the ground for a military coup.
Others pointed to fact that it is unprecedented in modern Turkey.
One Istanbul resident said: ‘Whoever makes mistakes must be held accountable whether it is an ordinary man or a Chief of Staff or a politician. Whoever acts against the people, illegally, and unjustly must face trial.’
Another added: ‘I am very sad. It should not have been like this. It seems there is really something going on behind the scenes. As far as I know the Chief of Staff shouldn’t be under arrest. What is his crime?’
Turkey’s military staged three coups d’etat between 1960 and 1980, and put pressure on another government to leave power in 1997.
It has long seen itself as the guardian of the country’s secular constitution.