Drumhead court-martial

A drumhead court-martial is a court-martial that happens on the battlefield to hear important charges of crimes that happened during the battle.
The term is said to come from the use of a drumhead as an improvised writing table.
Origins.
The earliest recorded use is in an English memoir of the Peninsular War (1807). The term sometimes is similar to summary justice. It has an implied lack of judicial neutrality, as noted in the transcripts of the trial at Nuremberg of Josef Bühler.