The medieval period started right after the decline of the Roman Empire's worldwide supremacy. We can also associate it with the rise of monotheism belief rooted in the Judaist beliefs, that are Christian and Islamic.
We also refer to that period as the dark ages, particularly related to feudal European history. We get many stories and legends from this turbulent historical period, and the most famous may be the Arthurian saga.
Even after centuries and countless interpretations and versions, this story of magic, courage, and mysticism still captivate.