<head>Capture of Prinassus</head>After this Philip, having delivered several assaults which proved futile owing to the strength of the place, again withdrew, sacking the small forts and country residences,
and when he had desisted from this, sat down before Prinassus. Having soon prepared pent-houses and other materials he began to besiege it by mining.
But when this project proved impracticable owing to the rocky nature of the ground he hit on the following device.
During the day he produced a noise underground as if the mines were going ahead, and at night he brought soil from elsewhere and heaped it round the mounds of the excavations, so that those in the town judging from the quantity of soil piled up might be alarmed.
At first the Prinassians held out valiantly, but when Philip sent to inform them that about two hundred feet of their wall had been underpinned and inquired whether they wished to withdraw under promise of safety or to perish all of them with their town after the underpinning had been fired, they believed what he said and surrendered the town.
Walbank Commentary