In the first three stanzas, the speaker notices a knight wandering among a pastoral landscape near nighttime. The knight is visibly wearied and fatigued, and the speaker wonders what could possibly befall him. It's late Autumn or early winter, and the birds are silent. While we don't know yet what happened to the knight, the speaker sets up the reader for the knight's story, establishing the poem's dreary tone and atmosphere.
The speaker directly addresses the knight he meets in the hillside, calling attention to the knight's vulnerability. The knight is "alone and palely loitering," his physical state mirrored by the landscape, which is a common feature of Romantic poetry. The grasses have withered, and the birds have grown silent. The harvest season is over, and the natural world prepares its transition into winter. The lily on the knight's brow suggests purity, innocence, and virtue: in spite of his haggard and woeful state, he retains the sense of honor and duty expected of a man of his stature. But the lily also symbolizes death, and as the speaker notices, the knight's face looks anguished and feverish, and the color is quickly draining from his cheeks.
Although the first three stanzas are relatively short, we can learn a remarkable amount about the knight, the speaker, and the poem’s conflict through the language and detail. First, we know that the knight is traveling alone and, based on his physical state, he’s been on the road for quite some time. Next, we know that it’s the end of autumn or early winter, because harvest time has ended and the grass has begun to wither and die. Finally, the symbolic juxtaposition of the lily and rose foregrounds a tension between purity and eros. The troubles the knight encountered on the road were likely erotic in nature.
From the repetition of “O what can ail thee, knight-at-arms,” we can deduce that danger lurks in the woods, and that the knight isn't exactly in the best shape to face any more impending challenges. By opening the poem with the question, the speaker begins a conversation that will last throughout the duration of the poem, and the majority of the poem is the knight's answer. What will the knight tell him when he begins to speak?