The conflict between Israel and Palestine is one of the bloodiest and longest-running in the world. There are intense feelings on both sides after decades of tragedy and numerous failed bids for lasting peace. Land that has been fought over for centuries has once again seen bloodshed with the attack by Hamas militants at the weekend and Israel's relentless bombing of the Gaza in response. Explaining the origins of the bitter conflict is difficult. In this story, Sky News seeks to examine some of the key events of the last 100 years in shaping that part of the Middle East...