It may be hard to believe, but statistical data shows that we are living during the most peaceful time in the history of the world. Atrocities like the Holocaust, Rwanda, and Darfur make it really hard to believe, though.
Hunter-gatherer societies lived up until 10,000 BC when governments and societies began to form and change the way of living. Speaking from percentage standpoints, there were more male deaths during that time per tribe than all the 20th century combined. Move forward to Bible times, there were so many wars between peoples and the punishment for most crimes was death.
Common in the Middle Ages and early modern times was to mutilate and torture for most crimes and use sadistic capital punishment like disembowling and burning at the stake. There was a long list of nonviolent crimes that were punishable by death, too. Also, slavery was more common than it is today. Though, it is very important to note that slavery is very much alive today and a multi-billion dollar industry in our world.
Homicides from the Middle Ages has greatly plummeted today and wars have also decreased significantly. Even from the 1950s until now there is a great decrease in deaths per war per year. In the 1950s it was 65,000 deaths per year per war and in the early 2000s it had decreased to 2,000. Genocide rates are down, too. We think our times are so violent because we have better press now that let's us know what is going on around us. We see the horrors, whereas before it wasn't well documented or publicized.