1915 (5 Oct) cover from Copenhagen to Belgium, franked with block of 4x5o green, showing various "Undeliverable (Enemy Country Return to Sender", "Zuruck", "Retour a L'Envoyer") handstamps, arriving back in Denmark on 8 October, minor cover folds at bottom, interesting usage from a neutral Denmark to German Occupied Belgium, possibly routed via England (Image)

Est.US$250