[14] [From Constantine Porphyrogenitus, The Embassies] Not long afterward Philip lent aid in Greece to the Romans in their against king . As they were moving against Antiochus in Asia, passing through and Macedonia by a difficult road, he escorted them with his own troops, supplied them with food and money, repaired the roads, bridged the unfordable streams, and dispersed the hostile Thracians, until he had conducted them to the . In return for these favors the Senate released his son Demetrius, who had been held by them as a hostage, and remitted the payments of money still due from him. But these Thracians fell upon the Romans when they were returning from their victory over Antiochus, when Philip was no longer with them, carried off booty and killed many - by which it was plainly shown how great a service Philip had rendered them when they were going.

[15] [From Constantine Porphyrogenitus, The Embassies] being ended, many of the Greeks charged Philip with doing or omitting various things, in disregard of the orders given by Flamininus when he settled the affairs of Greece. To answer these charges Demetrius went as an envoy to Rome on his father's behalf, the Romans being well pleased with him aforetime, when he had been a hostage, and Flamininus strongly recommending him to the Senate. As he was a very young man and somewhat flustered, they directed him to read his father's memorandum in which were written down, one by one, the things already done and those yet to be done, although decided upon contrary to justice; for, indeed, his unjust acts were prominent in the thought of many.

Nevertheless, the Senate, having regard to his late zeal in the matter of Antiochus, said that it would pardon him, but added that it did so on account of Demetrius. Philip, having been confessedly most useful to them in the war with Antiochus, when he might have done them the greatest damage if he had cooperated with Antiochus, as the latter asked him to, expecting much on this account and now seeing himself discredited and accused, and considered worthy of pardon rather than of gratitude, and even this merely on account of Demetrius, was indignant and angry, but concealed his feelings for a time. Afterwards, in a certain arbitration before the Romans, they transferred much of his territory to , seeking all the time to weaken him. Then, at once, he began secretly preparing for war.

[16] [From the Suda] Philip utterly destroyed all forces that sailed against him, lest the Romans should say that the Macedonian power was weakening.