By the term friends, or allies, used in this place, are not simply meant, those who are at peace with another power, but those who are engaged in the same war, and in a common cause with that power. So that all, who have come into the territories of such powers, are protected under the pledge of public faith. For it makes no difference with respect to persons or things, whether they are in the territories of those powers, or in their own. In the territory of a friendly power, who is not engaged in the same cause with either of two belligerent parties, prisoners of war do not change their condition, unless it has been agreed to the contrary by express treaty; as in the second treaty between the Romans and Carthaginians, it was stipulated that if any prisoners, taken by the Carthaginians from powers friendly to the Romans, should come into ports subject to the Roman people, their liberty might be claimed: and that powers friendly to the Carthaginians should enjoy the same privilege. For this reason, the Roman prisoners taken in the second Punic war, when sent into Greece, had not the right of postliminium there, the Greeks being entirely neutral, consequently they could not be released, till they were ransomed. III. According to the language of the ancient Romans, even free men might be restored by the right of postliminium. Gallus Ælius, in the first book of his explanation of law-terms, defines a person restored to his original situation by the right of postliminium, to be one, who had gone from his own country, in a free condition, to another, and returned to his own in consequence of such right. By the right of postliminium a slave also who has fallen into the hands of an enemy, upon his release from thence, returns to the service of his former master. As to the law of postliminium, horses, mules, and ships are considered in the same light as slaves. And whatever advantage this law gives any one in recovering persons or things from an enemy, the enemy in his turn has equal advantage from the same law. But modern lawyers have made a distinction between two kinds of postliminium, by one of which, persons returned to their former condition, and by the other, things are recovered. IV. The right of postliminium may extend to those, who are seized and detained in an enemy's country upon the breaking out of war. For though during the continuance of that war, there may be reason for detaining them, in order to weaken the enemy's strength, yet, upon the conclusion of a peace, no such motive and pretence can be devised for their release being refused or delayed. It is a settled point therefore that upon peace being made, prisoners of the above description always obtain their liberty, their claim to it being universally acknowledged.