The oldest form of power was and has always been, gold. The more gold you possess, the more power you wield. This is also why pirates would burry their gold. If they ever get raided and somehow survive, they'll need a stash to ensure some of their power.
This is also why dragons were so powerful. With their absurd stashes, they were essentially immortal. Over time, their stashes dwindled. With it, their powers slowly faded causing them to shrink.