Ross Rocklynne's "Interlude" (short story, time travel, free): When a caveman freed an advanced civilization of a dictator
Two of the ruled plot his overthrow. If only they could bring a 20th century uncollared (hence unslaved) man (why of 20th century?) who will overthrow the dictator. Their experimental time machine instead will bring back a caveman from 100,000 years ago. A man who craves to be a tribal chief.
Some unlikely adventures follow & the world is freed of the dictator.
Fact sheet.First published: Astounding, December 1942.
Download full text as part of the scans of the magazine it originally appeared in.
Among the stories from Astounding/Analog issues edited by John Campbell.
Related: Stories of Ross Rocklynne.