And did those feet in ancient time Walk upon England's mountains green:
The speaker opens the poem with a question (don't worry that there's not a question mark there yet, it'll probably show up later).
He asks if "those feet" walked upon England's green mountains in ancient times.
The real question is, whose feet is the speaker talking about? Some ancient English king, such as King Arthur?
We're not gonna mince words, Shmoopers: we have no idea who the speaker is talking about just yet, but it's obviously somebody who lived a long time ago (in "ancient" times).
Let's move on in this first stanza so we can figure out the solution to this little riddle.
And was the holy Lamb of God, On England's pleasant pastures seen!
The speaker is clearly in an interrogatory mood.
He now asks if the "holy Lamb of God" was on England's "pleasant pastures." (Note the funky word order in this stanza, folks.)
We definitely have to go over a few things here.
First off, what or who is the Lamb of God? We'll give you a hint, it's not this metal band from Virginia. Nope, "Lamb of God" is a phrase that first appears in the Gospel of John in the New Testament. (You can read more about why Jesus is called the Lamb of God right here if you'd like.) All you need to know for our purposes is that the speaker of this poem is clearly referring to Jesus, the sacrificial "lamb" who died for all mankind's sins (or so the Christian teaching goes).
Okay so he's definitely talking about Jesus in lines 3-4, but do "those feet" also belong to Jesus, too? It's a bit hard to say at this point, but all signs point to a big, gigantic, enormous "yes."
So, why is the speaker asking if Jesus walked among the hills of England in ancient times? Didn't Jesus live somewhere in what is now Israel?
Actually, there was a popular legend in England in Blake's day that held that Jesus visited England with his uncle, Joseph of Arimathea, sometime between the ages of 12 and 30 (the so-called "lost years").
It sounds kind of bogus, sure, but there are plenty of scholars who have been willing to take the idea seriously, as you can see in this documentary and in this book.
The origins of this little legend are a little unclear, but being a mythologizer himself, Blake was willing to entertain all kinds of ideas. In Milton, A Poem, for example (the larger work to which "Jerusalem" is a preface), the British poet John Milton is up in Heaven, but then travels to earth in the form of a comet and enters Blake's foot. In the poem, Milton is clearly a Christ-like figure, and he comes back to England to redeem the errors he made the first time around (these errors are complicated and unclear, so we'll just leave it at that). Blake is the vehicle through which Milton is able to reenter the "real" world and fix everything he messed up.
Keeping all this in mind, it makes sense that Blake would explore the legend of Jesus traveling to England in "ancient time" in a poem that is about a guy (Milton) whom Blake sees as similar to Jesus. The Jesus of "Jerusalem" visiting England is a parallel for the John Milton Blake describes in the poem.
(You can read more about Blake's Miltonright here if you'd like. Be warned: the poem is long, complicated, confusing, maddening, and overall a very difficult slog. Don't worry, though, Blake wanted it that way. It's not you, it's him—seriously.)
Before we go on, let's say a few things about the form of "Jerusalem":
We've got four lines in each of the poem's four stanzas. These are called quatrains. Each line in the quatrain is written in iambic tetrameter, which means each line contains four iambs.
We'll have more to say about the form and meter of this poem over in… "Form and Meter," so if you're dying for a more thorough analysis, head over there.