What breeding makes up the Irish thoroughbred horse?

I have an Irish thoroughbred and I don't know a lot about him or the breed. I know he comes from the Coolmore stud or at least his sire did/does. I'm really interested as to what makes up the breed, people tell me that he's just Irish Draught X TB but upon further research I found some web pages saying that they are purely thoroughbreds from Ireland hence Irish TB. I'm hoping that if I can find more out about his breeding and temperament I can bring him on with better knowledge and understanding of his behaviour, Thanks(: