QSO 0957+561A/B, UMa Double Quasar: 8 Billion Light Years
The double quasar in Ursa Major can be seen from Gloucester on a clear, dark night. You'll need a fairly large telescope, but with patience you can see this light with your own eyes. The object itself is actually a single entity, a fantastically active galaxy core whose light is bent by gravity around an intervening galaxy cluster, so that it appears to be two images rather than one.
Our sun is about 5 billion years old. When this light began its journey, 8 billion years ago, there was no earth, no sun, no solar system, and there wouldn't be for another 3 billion years. You're looking more than half way back to the beginning of time here.