Passage 1.36.6
ὡς δὲ καὶ ἐξ Αἰγύπτου καὶ Μυσίας καὶ παρὰ τῶν Κρητῶν τὰ πολλὰ ὑστέριζον αἱ βοήθειαι, Ῥόδιοι δὲ μόναις ναυσὶν ἰσχύοντες πρὸς ὁπλίτας τοὺς Μακεδόνας οὐ μεγάλα ὠφέλουν, ἐνταῦθα Κηφισόδωρος ἐς Ἰταλίαν σὺν ἄλλοις Ἀθηναίων πλεύσας ἱκέτευεν ἀμῦναι Ῥωμαίους· οἱ δέ σφισι δύναμιν καὶ στρατηγὸν πέμπουσιν, οἳ τὰ Φιλίππου καὶ Μακεδόνων ἐς τοσοῦτο καθεῖλον ὡς ὕστερον Περσέα τὸν Φιλίππου τήν τε ἀρχὴν ἀποβαλεῖν καὶ αὐτὸν αἰχμάλωτον ἐς Ἰταλίαν ἀχθῆναι. Φίλιππος δὲ ἦν οὗτος ὁ Δημητρίου· πρῶτος γὰρ ταύτης τῆς οἰκίας ἔσχε Δημήτριος τὴν Μακεδόνων ἀρχὴν ἀποκτείνας Ἀλέξανδρον τὸν Κασσάνδρου παῖδα, ὡς τὰ πρότερον ἔχει μοι τοῦ λόγου.
But as aid from Egypt, Mysia, and Crete came mostly too late, and the Rhodians, powerful only in ships, could offer little effective help against Macedonian infantry, Kephisodoros sailed to Italy with other Athenians and pleaded with the Romans for protection. The Romans sent them a force and a general, who weakened Philip and the Macedonians to such an extent that later Perseus, the son of Philip, lost his kingdom and himself was taken prisoner and brought captive to Italy. This was Philip, the son of Demetrios; for Demetrios was the first of this house who gained rule over Macedon, having killed Alexander, son of Kassander, as I mentioned earlier in my narrative.