[1] David Innes is introduced in the first Pellucidar novel, At the Earth's Core, as a mining heir who finances the experimental "iron mole," an excavating vehicle designed by his elderly inventor friend Abner Perry.

It is inhabited by prehistoric creatures of all geological eras, and dominated by the Mahars, a species of flying reptile both intelligent and civilized, but which enslaves and preys on the local stone-age humans.

The books after the first two show Innes' new empire as a relatively small entity in a world by and large still primitive and savage, and even his own subjects as little affected or changed by the trappings of civilization.

In response to Perry's plea, an outer world expedition is launched to rescue Innes, in which Burrough's jungle hero Tarzan plays a major role.

Savage Pellucidar, the final book in the series, presents a new sequence of adventures for Innes, Perry, and Dian, in which a hitherto unknown native Bronze Age civilization is discovered.