November 27, 1095 - Crusades Begin in Clermont, France

History has shown us one of the best ways to cure rivalries is to have a common enemy.  As the papacy's influence grew in the Middle Ages, and as kings and emperors sought/fought for power, Christianity had a great deal of infighting.  But on November 27, 1095, Pope Urban II solidified Christianity when he began the great crusades in Clermont, France.  The goal was to rid the Holy Land of Islamic rule, and people focused on a common enemy for sure, but untold thousands were killed over the next couple of decades.