Throughout history war has always been a highly codified form of armed violence. For example, the white flag to surrender or request a meeting to agree surrender terms was already being used during the Roman Empire and in the Middle Ages and the idea of a truce to temporarily stop the fighting emerged in the 13th century.
However, in the 19th century war was transformed by mass conscription of soldiers and the emergence of technologies of mass destruction. There was a growing belief that more needed to be done to protect the wounded, prisoners of war and civilians innocently caught up in the conflict.
A number of international conventions were agreed, including the Hague Conventions 1899-1907 and the Geneva conventions from 1864 to 1929. In addition many countries introduced their own military codes which also specified the punishments for soldiers if these codes were broken.
The “total wars” of the 20th century challenged all previous attempts to codify and “civilize” war. Violence towards civilians increased greatly after World War I, often to demoralise and terrorise whole populations into surrender. The distinction between military forces and civilians became increasingly blurred during the 20th century.
The massacre at Monte Sole, which took place in 1944 in northern Italy, is an example of civilians being made the principal target of an occupying army. Their basic rights in times of war were ignored and many were annihilated.