Belligerents hold prisoners of war in custody for a range of legitimate and illegitimate reasons, such as isolating them from enemy combatants still in the field (releasing and repatriating them in an orderly manner after hostilities), demonstrating military victory, punishing them, prosecuting them for war crimes, exploiting them for their labour, recruiting or even conscripting them as their own combatants, collecting military and political intelligence from them, or indoctrinating them in new political or religious beliefs.For most of human history, depending on the culture of the victors, enemy combatants on the losing side in a battle who had surrendered and been taken as a prisoner of war could expect to be either slaughtered or enslaved.The Leipzig citizen Rochlitz remarked in his account about the Battle of Leipzig, that large crowds of French POWs were held on fields outside the town, begged passersby for food, and that most of them didn't survive this ordeal.
Sometimes, the purpose of a battle, if not a war, was to capture women, a practice known as raptio; the Rape of the Sabines was a large mass abduction by the founders of Rome.
Typically women had no rights, and were held legally as chattel.
Some Native Americans continued to capture Europeans and use them both as labourers and bargaining chips into the 19th century; see for example John R.
Jewitt, an Englishman who wrote a memoir about his years as a captive of the Nootka people on the Pacific Northwest coast from 1802–1805.
During his lifetime, Muhammad made it the responsibility of the Islamic government to provide food and clothing, on a reasonable basis, to captives, regardless of their religion; however if the prisoners were in the custody of a person, then the responsibility was on the individual.
The 1648 Peace of Westphalia, which ended the Thirty Years' War, established the rule that prisoners of war should be released without ransom at the end of hostilities and that they should be allowed to return to their homelands.In Christian Europe, the extermination of heretics was considered desirable.Examples include the 13th century Albigensian Crusade and the Northern Crusades.Noblemen could hope to be ransomed; their families would have to send to their captors large sums of wealth commensurate with the social status of the captive.In feudal Japan there was no custom of ransoming prisoners of war, who were for the most part summarily executed.About 100 senior officers and some civilians "of good social standing", mainly passengers on captured ships and the wives of some officers, were given parole d'honneur outside the prison, mainly in Peterborough although some further afield in Northampton, Plymouth, Melrose and Abergavenny.