A court-martial is a military court which hears and judges legal charges brought against people in the armed forces.
Until the 16th century, soldiers had no rights, and were subject entirely to their commanders. In 1689, the first real military judicial process was enacted with the British Mutiny Act, which provided for legal discipline of a standing army. Most countries (Germany being an important exception, using only civilian courts) now have separate military codes of justice, administered by separate military courts, though (usually) subject to civilian appeal and review.
There are two main types of courts-martial, general and special. Only a high ranking commander, general, or flag officer may convene a general court-martial. A special court-martial may be initiated by a brigade or regiment officer. A general court-martial may impose any penalty, whereas a special court-martial may impose only short term confinement and/or dishonorable discharge.
The officer convening the court-martial chooses officers from his command to sit as judges.
researched from the 1969 Encyclopedia Britannica