The speaker
A man who notices a fellow knight wandering through a chilly hillside one evening.
The knight
The "haggard" knight who appears to the speaker on a hillside, and relates to the speaker his encounter with a beautiful woman on the same hillside.
The beautiful woman
A mysterious, enchanting woman who lives in the hillside. She possesses supernatural charms, and each man she meets succumbs to the power of her spells.
The pale kings, princes, and warriors
The characters the knight meets during his dream on the hillside who, like him, fell beneath the woman's charms.