The origin of the word postliminy

Just as in regard to those things which are captured from the enemy, so also in regard to the right of postliminy (postliminium), no very sound view has been advanced by those who in more recent times have laid claim to a knowledge of the law. The subject was treated with greater painstaking by the ancient Romans, but often rather confusedly, so that the reader could not distinguish what they ascribed to the law of nations and what to the Roman civil law.

Where postliminy may occur

Postliminy, therefore, is a right which arises from a return to the threshold, that is, to the public boundaries. Thus Pomponius says that he who has begun to be within our fortified lines has returned by postliminy. Paul the Jurist defines such a return when the captive has entered our frontier.

On similar grounds, the agreement of nations [holds] that postliminy occurs if a man, or a thing of the sort in regard to which it has been decided that postliminy is possible, has come [into the territory of our friends or allies]. … [W]e are to understand as friends or allies not merely those with whom we are at peace, but those who take the same side in a war. Those who come to such friends … begin to be protected in the name of the state. It makes no difference in fact whether a man or thing has come to them or to his own people.