Information structure in the noun phrase remains unexplored or limited to the study of the s-form and the of-form in English, which are interpreted from the perspective of the Prague School. Accordingly, the prenominal s-form is chosen if the possessor expresses old information; conversely, if the possessor expresses new information, the postnominal of-form is preferred. Ancient Greek, however, indicates that this is not the sole pattern attested. In our data, drawn from Herodotus, a postposed genitive refers to the topic of the immediately preceding clauses, and has no semantically compatible referent around it. Preposed genitives denote new or discontinuous participants, and are used in contrastive and emphatic contexts. In this case, the principle “rheme before theme” can be identified.