There has been high drama in Turkey on the day its governing party was put on trial and forced to fight for political survival.
Ahead of the hearing, authorities detained more than 20 people, said to include a senior journalist and several retired leading members of the military.
Police moved in as part of a widening investigation into a suspected coup plot against the government.
Prime Minister Recep Tayyip Erdogan said the detentions were linked to a probe into Ergenekon, a shadowy, ultra-nationalist and hardline secularist group.
But Erdogan had other concerns today as the Constitutional Court began hearing a legal case in which his AK Party is charged with trying to establish an Islamic state in the secular Turkish Republic.
The party could be closed down, which could lead to an early election. While its roots are in political Islam, the AK Party denies any suggestion it aims to introduce Islamic law.