There is probably no branch of the laws of war which stands in greater need of explanatory comment than do the chapters relating to prisoners of war. The generation preceding the great peace conferences at The Hague was marked by a number of important wars of which continental Europe was the theater; during these conflicts the number of persons reduced to captivity surpassed all experience, as did the number of problems which arose in connection with their safe-keeping and repatriation; but during the entire period the regulations governing their administration and detention remained substantially unchanged. It is true that several European states caused their regulations in that regard to be revised, but as those regulations were strictly internal in character and had no external operation, save in the territory of the enemy which they held in military occupation, the condition of prisoners of war remained substantially unchanged. Indeed, until the condition of this unfortunate class was made the subject of conventional regulation at The Hague, but few important ameliorations had been brought about in their status since the activity of the Emperor Napoleon was brought to a close at the battle of Waterloo.