Dative: possessor as modifier

Syntactical Level

τῶν μοι παίδων ἕνα παράλυσον τῆς στρατηίης τὸν πρεσβύτατον

Exempt one of my sons from military service, the eldest.

The dative signals a possessor as a modifier.

Syntactic behaviour

The noun with which this modifier stands is invariably in the genitive. This indicates that Greek has recourse to a dative in order to avoid a double genitive.

Example Sentences: 

ἄρχεται δὲ ὁ πόλεμος ἐνθένδε ἤδη Ἀθηναίων καὶ Πελοποννησίων καὶ τῶν ἑκατέροις ξυμμάχων

Al van dan af brak de oorlog tussen de Atheners, de Peloponnesiërs en hun beider strijdmakkers uit.