In thy faint slumbers I by thee have watch'd, And heard thee murmur tales of iron wars... Thy spirit within thee hath been so at war And thus hath so bestirr'd thee in thy sleep, That beads of sweat have stood upon thy brow Like bubbles in a late-disturbed stream; And in thy face strange motions have appear'd, Such as we see when men restrain their breath On some great sudden hest. O, what portents are these? Some heavy business hath my lord in hand, William Shakespeare, Henry IV, Part 1, Act 2, Scene III Warkworth Castle, Northumberland - I was there on a bright day last Summer. But this is really what it felt like. It was besieged & taken by Henry IV in 1405 and appears in Shakespeare's play, the above lines describing the depth of Hotspur's obssession with overthrowing the King - they didn't inspire the pic, but I thought they fitted pretty well.