Isaac Asimov describes a similar situation about the downfall of the Galactic Empire in „Foundations“
It's basically the fall of the Roman Empire, but set in the future and with a outpost at the edge of the galaxy to preserve some of the knowledge across the dark ages.
It's basically the fall of the Roman Empire, but set in the future and with a outpost at the edge of the galaxy to preserve some of the knowledge across the dark ages.