William Blake. From "Milton".

And did those feet in ancient time     Walk upon England’s mountains green?  And was the holy Lamb of God     On England’s pleasant pastures seen?    And did the Countenance Divine        Shine forth upon our clouded hills?  And was Jerusalem builded here     Among these dark Satanic Mills?    Bring me my bow of burning gold!     Bring me my arrows of desire!  Bring me my spear! O clouds, unfold!     Bring me my chariot of fire!    I will not cease from mental fight,     Nor shall my sword sleep in my hand,  Till we have built Jerusalem       In England’s green and pleasant land.