I think it's just the huge corpus of fiction that centers around that time frame. Our modern culture is directly descendent of that. Concepts like master bedroo

I think it's just the huge corpus of fiction that centers around that time frame. Our modern culture is directly descendent of that. Concepts like master bedroom, inheritance, formal titles like sir, King James bible and its older English wording, Shakespeare, King Arthur, etc etc. There are massive stone works and cathedrals from that timeframe still around today in Europe. Many fairy tales and myths and legends were created in that time that colored fiction for the next 500-1000 years into modern day.