Historical Fantasy

It is interesting to note how certain genres or styles are inexplicably linked to specific eras in history. For example, fantasy video games, movies, shows or franchises such as the Witcher, Game of Thrones, and others are often stylized to reflect Medieval era.
In the same way, the Steampunk aesthetic is rooted in Victorian England pieces.
It would be an interesting analysis to explore how Medieval literature such as the Canterbury Tales, Troilus and Criseida, Sir Gawin and the Green Knight and others held fantasy elements in their foundation which laid the groundwork for it becoming a framework for modern fantasy works.
In the same way, the steampunk elements pulled from the Victorian Era can be analyzed in context of the boom of the industrial revolution.
What was the path to these connections of era and aesthetic? Where were its modern origins? And what is it about these historical movements in society and literature that made them withstand modernization while preserving these core elements?