21. Philip, lest his troops should be enervated by inactivity, and at the same time, to avert all suspicion of his harbouring any design of a war with Rome, ordered his army to assemble at Stobi, in Pæonia; and thence he led it on into Mædica. He had been seized with an earnest desire of ascending to the summit of Mount Hæmus, for he gave credit to a vulgar opinion, that from thence could be seen at once the Pontic and Adriatic Seas, the river Danube, and the Alps; and he thought that the having a view of all those places, would be of no small consequence towards forming his plans of a war with Rome. On inquiry, from people acquainted with the country, respecting the ascent to Mount Hæmus, when it was ascertained from them all, that there was no way by which an army could go up it, but that there was access for a small party, lightly accoutred, that he might soothe with familiar discourse his younger son, whom he had determined not to take with him, he first asked his opinion, “whether, as the difficulty of the journey was represented to be so great, he ought to persist in his design, or not?” He added, that, if he should resolve to proceed, he could not forget the caution of Antigonus, respecting undertakings of that kind; who being tossed about by a violent storm, when he had all his family in the same ship with him, was said to have advised his sons to remember, and hand down to their children, this maxim: “never to have the hardihood to rush into danger themselves, and their whole family together.” He would therefore attend to this warning, and not expose his two sons at once to the chance of those perils, which were represented to lie in his way; and as he meant to take his elder son with him, he would send back the younger into Macedon, as a reserve to his hopes, and as guardian of the kingdom. It did not escape Demetrius that he was sent out of the way, that lie might not be present at their deliberations, when, in view of those places, they should consult which were the shortest roads to the Adriatic Sea and to Italy, and what was the general plan to be pursued in the war. He was obliged however not only to obey his father on the occasion, but to express his approbation of the measure, lest a reluctant obedience might beget suspicion. In order that his journey into Macedonia might be safe, Didas, one of the king’s general officers and governor of Pæonia, was ordered to escort him with a small party of men. Perseus took this man, as well as most of his father’s friends, into the conspiracy to ruin his brother, from the time that it became plain to every one, from the tendency of the king’s feelings, to which of the two the inheritance of the throne should come; and Perseus charged him on this occasion, to insinuate himself by every kind of obsequiousness into the most familiar communication with Demetrius, so as to draw from him all his secrets, and to pry into his hidden thoughts. The prince, therefore, set out with