"The Three Ravens" (Roud 5, Child 26) is an English folk ballad, printed in the songbook Melismata[1] compiled by Thomas Ravenscroft and published in 1611, but the song is possibly older than that.
Furthermore, a "fallow doe", a metaphor for the knight's pregnant ("as great with young as she might go") lover or mistress (see "leman") comes to his body, kisses his wounds, bears him away, and buries him, leaving the ravens without a meal.
Rather than commenting on the loyalty of the knight's beasts, the corbies see that the hawk and the hound have forsaken their master, and are off chasing other game, while his mistress has already taken another lover.
They talk in gruesome detail about the meal they will make of him, plucking out his eyes and using his hair for their nests.
The loneliness and despair of the song are summed up in the final couplets; There are a few different versions of this anonymously authored poem.