John Keats was a poet of imagination and idealism. He was intrigued by the theme of medievalism that he employed in many of his poems.
Keats’ poem The Eve of St. Agnes has many elements of “medievalism” and medieval romance. First of all, the setting of the story is a castle, which was one of the most common medieval settings. Added to this is the occurrence of the events in a cold, wintery midnight. These create a perfect medieval atmosphere.
St. Agnes' Eve--Ah, bitter chill it was!
The owl, for all his feathers, was a-cold;
The hare limp'd trembling through the frozen grass,
The characterisation of the major characters has a medieval touch too. Chastity, virginity, knighthood and chivalry were the major themes of medieval romance. As we see, “virginity” is quite stressed. The title of the poem is, in fact, taken from the patron saint of young virgins, i.e. St. Agnes.
Past the sweet Virgin's picture, while his prayer he saith
Young virgins might have visions of delight,
Hence, Madeline is depicted as young, a virgin delicate and very lovely, and Porphyro is shown as a brave and courageous knight who risks his life to get his lady.
The poem is known for its striking visual and sensual imagery.
Full on this casement shone the wintry moon,
And threw warm gules on Madeline's fair breast
Madeline’s dream, vision and magic spell add a dash of supernaturalism to the story. Performing of a ritual to see future husband accounts for medieval superstition. Just like a medieval fairy tale, Porphyro, transcending barriers of the family feud, takes Madeline along with him, and this invokes thrill and adventure.
And they are gone: aye, ages long ago
These lovers fled away into the storm
Also, Keats used the form of a narrative verse, which was a famous poetic tradition amongst the medieval poets. All of these things combine to transport the readers to the realm of medieval milieu.