"With how sad steps, O Moon, thou climb'st the skies!" is a pretty mysterious title if there ever was one. To be fair to the title, it's not really the title in the traditional sense. Like many sonnets, the first line is used in place of a title. This poem is the 31st poem in Sidney's sonnet sequence Astrophel and Stella. Occasionally, you will see it printed as just "Sonnet 31." B-O-R-I-N-G. Others, like us here at Shmoop, use the first line as the title because, quite frankly, it's way cooler.
Still, that line is kind of a doozy. How can steps be sad? And how can a Moon take any kind of steps at all? Do they have escalators in the heavens? What's the significance? Deep breath, Shmoopers. This is where we come in.
The title is about making connections, really, between the speaker and the moon. It sets us up for the poem's main talking point: how the Moon and the Astrophel are kind of the same. The Moon looks like he's lovesick, and Astrophel knows it because, well, he feels the same way. They are, more or less, in the same boat. The title, in all its ambiguous glory, reflects this identity because, well, the "sad steps" could belong to either Astrophel or the Moon—or both.
The title is mysterious in another way as well. We really have no clue just what this poem is about, what the deal with the sad steps are, why the speaker is talking to the Moon, etc. While we eventually get answers for some of those questions, much remains unanswered in the poem (what has Stella done to make the speaker so upset?). The vagueness of the title anticipates some of the vagueness of the poem that follows. Ah, but such is love, gang.