Est et alia in monumentis rerum Graecarum profunda quaedam et inopinabilis latebra barbarico astu excogitata. Histiaeus nomine fuit, loco natus in terra Asia non ignobili. Asiam tunc tenebat imperio rex Darius. is Histiaeus, cum in Persis apud Darium esset, Aristagorae cuipiam res quasdam occultas nuntiare furtivo scripto volebat. comminiscitur opertum hoc litterarum admirandum. servo suo diu oculos aegros habenti capillum ex capite omni tamquam medendi gratia deradit caputque eius leve in litterarum formas compungit. his litteris quae voluerat perscripsit, hominem postea quoad capillus adolesceret domo continuit. ubi id factum est, ire ad Aristagoran iubet et “cum ad eum,” inquit, “veneris, mandasse me dicito ut caput tuum, sicut nuper egomet feci, deradat.” servus, ut imperatum erat, ad Aristagoran venit mandatumque domini adfert. atque ille id non esse frustra ratus, quod erat mandatum, fecit. ita litterae perlatae sunt.
(Aulus Gellius, Noctes Atticae 17.18-27)
There is also in the records of Grecian history another profound and difficult method of concealment, devised by a barbarian’s cunning. He was called Histiaeus and was born in the land of Asia in no mean station. At that time king Darius held sway in Asia. This Histiaeus, being in Persia with Darius, wished to send a confidential message to a certain Aristagoras in a secret manner. He devised this remarkable method of concealing a letter. He shaved all the hair from the head of a slave of his who had long suffered from weak eyes, as if for the purpose of treatment. Then he tattooed the forms of the letters on his smooth head. When in this way he had written what he wisehd, he kept the man at home for a time, until his hair grew out. When this happened, he ordered him to go to Aristagoras, adding: “When you come to him, say that I told him to shave your head, as I did a little while ago.” The slave, as he was bidden, came to Aristagoras and delivered his master’s order. Aristagoras, thinking that the command must have some reason, did as he was directed. And thus the letter reached its destination. (tr. John C. Rolfe)