The epic poem Jerusalem was in Blake's own opinion his masterpiece. It is the last of the great prophetic books. Originally produced as an engraved book of 100 pages (only one copy of which was every fully finished in the colouring), the poem develops and unifies many of the themes Blake had been exploring in earlier works. It is a complex and powerful work, full of dramatic imagery and sublime poetry. You might think of it like a poetic version of a Wagner opera. This is poetry as if your life depended on it. It is amazing how contemporary to us it feels if you compare it to what was being produced at the time. You can see in this work how it has inspired writers like Phillip Pullman in his Northern Lights trilogy. The edition read here is the first printed version of the poem - which was impossibly hard to read in the original. This then was the first opportunity to really explore it. In his introduction Blake implies that the way to experience this work is to read it aloud rather than in your head. I can only agree and this opens another dimension to what was alreay a textual and pictorial artwork.