The catholic church was the dominant religion in most of Europe. On the edges, where it ran into Islam there was constant turmoil. The pagan Vikings were also constantly attacking.
Meanwhile, there was plenty of low-level internecine fighting among xtian nobles.
In fact, one reason for the Crusades was a desire by the church to re-direct that internal blood-letting to a more useful purpose.
A few more atheists might have helped but it would merely have given the catholics someone else to kill. They were perfectly willing to kill heretics wherever they found them.
Meanwhile, there was plenty of low-level internecine fighting among xtian nobles.
In fact, one reason for the Crusades was a desire by the church to re-direct that internal blood-letting to a more useful purpose.
A few more atheists might have helped but it would merely have given the catholics someone else to kill. They were perfectly willing to kill heretics wherever they found them.
