According to Genesis, Abraham and his family originally lived in Canaan. However, Jacob (Israel) and his sons moved to Egypt to take advantage of Joseph's high place there. By the time of Exodus, however, the descendants of Israel had all been enslaved. Charlton Heston came along and led them into the Sinai Desert. Eventually, they came back to Canaan, finding it fully populated with people already.
After this, Canaan became a fairly bloody place. The Israelites fought the Moabites, the Amalekites, and everyone else in their way. At various times, various nearby empires attacked as well. This is not too different from now, actually.