Dear Ash;

In answer to your question via text message, although I’m sure the moment of relevance has passed, since you were, at the time, invovled in a pub quiz- Your question: What are the four horcruxes?

  1. I find a problem with the question in the first place because there aren’t four, there are seven.
  2. No matter, I will answer your question and link you to the Harry Potter Wiki.

Here they are:

  1. Tom Riddle’s Diary
  2. Marvolo Gaunt’s Ring
  3. Slytherin’s Locket
  4. Hufflepuff’s Cup
  5. Ravenclaw’s Diadem
  6. Harry Potter himself
  7. Voldemort’s snake Nagini

So there you are, consider yourself education. Although for the detailed list which includes location/who destroyed it etc consider the Wiki here