German military law
The trial of Peter von Hagenbach by an ad hoc tribunal of the Holy Roman Empire in 1474 was the first "international" recognition of commanders' obligations to act lawfully.
Also, on October 14, 1915, Heynen stood accused of having threatened the POWs under his command with summary execution if they did not immediately return to work during an attempted strike action.
[9] Of those enemy nationals who were prosecuted, especially well-known is the case of Edith Cavell, a British Intelligence operative under International Red Cross cover,[10] who was court-martialled and sentenced to death in Occupied Belgium for, among many other things, helping an estimated 200 escaped British POW's to cross the lines and return to active service – which in wartime was indeed a death penalty offence for civilians under the German military law in the German Empire.
Cavell was also convicted of perfidy, for having used the international legal protection given by her position as a Red Cross nurse as a cover for violating medical neutrality during wartime.
Belgian national Gabrielle Petit, a fellow British Intelligence field agent for La Dame Blanche spy ring in occupied Belgium, was similarly court-martialed as a civilian subject to service discipline, convicted of espionage, and executed by firing squad on 1 April 1916.
A directive on a special criminal law of war was already enacted on 17 August 1938 by OKW chief Wilhelm Keitel at the behest of Führer Adolf Hitler.
The Reichskriegsgericht acted as the first and last resort for 44 criminal offenses under penalty of death such as the following: With the arms buildup and continued warfare, the number of Wehrmacht courts-martial increased to over 1,000.
On 13 May 1941 Hitler had Keitel pass a directive, according to which any Wehrmacht officer had the authority to execute accused civilians in the area of Operation Barbarossa and the Eastern Front without trial.
Against the laws of war, the official repeal of criminal prosecution led to widespread hostage-taking, mass executions, burning and looting by German forces.
At the same time, according to historian Alfred Maurice de Zayas, senior Wehrmacht commanders with more traditional views of service honour insisted upon court martial prosecutions of German soldiers who stood accused of crimes against civilians in occupied countries or for massacres or other mistreatment of POWs.
Several military lawyers and judges, including Karl Sack, Rudolf Schleicher, and Helmuth James von Moltke, were executed by following the failure of the July 20th Plot against the life of Adolf Hitler.
