The poem is intense and frightening; bleak and dark. Its apocalyptic visions fit right into our Hunger Games - World War Z - end times-end of the world Armageddon culture.
It's read aloud brilliantly here: Darkness by Lord Byron read by Tom O'Bedlam. Take five minutes to listen; I promise you won't be disappointed.
It was written, fittingly, in 1816 - the year without a summer. A podcast I listened to (In Our Time) had an episode about this very summer, and actually started me on this quest to read the Romantic poets. That year was dark and cold and bleak and frightening, and although it was not as bad as Lord Byron depicts in his poem, it was still pretty dismal.
Another thing that kept coming to my mind was the old cartoon from 1939 in which the animals gather to talk about the war that killed off all mankind. It's on youtube here: Peace on Earth.
It's that last line though, that made me love this poem. So fucking brilliant. I have felt very so-so about the poetry of Lord Byron, but now I understand his rock start status.