What's beef?

It's somewhat of a cliché to say that the truest essence of hip-hop is in the battle but after 40-years of hip-hop, there is bound to be some long-lasting ill-will amongst a group of people as competitive as rappers. Some beef never gets squashed and can go on for years between rappers who never get over that initial slight.

In fact, it was just last week when two rappers took to the airwaves to publicly re-hash decade-old beef. First, Cam'ron claimed that his old rival Jay Z was refusing to play his music at Hov's famed 40/40 Club in New York City, indicating the former Roc-A-Fella stars rivalry was still going on strong. Meanwhile, Game decided to fire another shot  in his never-ending feud with 50 Cent.

In wake of this news, XXL is looking back at 9 of hip-hop's longest-lasting feuds as we wonder why it can't be all so simple.