Priam was the king of Troy during the Trojan War. This war was the last for Troy, as the city fell and was destroyed. In the war, Troy - and its leader - were trying to "hold out" against the Greek army. Similarly, Old Ben represents the last hold of nature on encroaching civilization. Ben's death is symbolic of the death of nature. Nature, like Priam, is a king of old trying to survive in a changing world, but ultimately failing.