Uno More Frage

My question should be fairly simple to answer; I'm just a little bit confused. It's about chapter 42 when Abel Magwitch tells Pip and Herbert about Compeyson. I understand that Compeyson is the second convict that was fighting Magwitch in the beginning of the story. Magwitch was also his partner in crime while they attempted to lure Miss Havisham away from her money. I know that now Abel and Compeyson hate each other to death but I have no idea how this hate escalated to such a height and why the two want each other dead. Can I please get some help with this? Thank you.