Passage 1.6.1
τὰ δὲ ἐς Ἄτταλον καὶ Πτολεμαῖον ἡλικίᾳ τε ἦν ἀρχαιότερα, ὡς μὴ μένειν ἔτι τὴν φήμην αὐτῶν, καὶ οἱ συγγενόμενοι τοῖς βασιλεῦσιν ἐπὶ συγγραφῇ τῶν ἔργων καὶ πρότερον ἔτι ἠμελήθησαν· τούτων ἕνεκά μοι καὶ τὰ τῶνδε ἐπῆλθε δηλῶσαι ἔργα τε ὁποῖα ἔπραξαν καὶ ὡς ἐς τοὺς πατέρας αὐτῶν περιεχώρησεν Αἰγύπτου καὶ ἡ Μυσῶν καὶ τῶν προσοίκων ἀρχή.
Concerning the actions of Attalus and Ptolemy—they were of such a great age that their fame no longer endures, and even those who associated with the kings and wrote the accounts of their deeds had previously shown insufficient care. For these reasons it has occurred to me also to relate their deeds—of what nature they were and how the kingdoms of Egypt and Mysia, as well as those of nearby peoples, came into the power of their forefathers.