They are the group that Rome slaughtered, men, women, and children, including babies.
Roman soldiers, gathered from ALL OVER THE ROMAN empire, kept the PAX ROMANA for centuries. And they weren't the first "empire" to slaughter millions. I guess you didn't read any history or don't remember that the history of the human race is a history of war.
Most historians agree that Genghis Khan was the mass murderer to end all mass murderers.
After he burned, looted, destroyed, etc., town after town all across the continent of Asia he would RETURN there not long after because he knew that people HID their money, treasures and daughters.
He would finish his massacre.
Google:
Genghis Khan(born Temüjin,[note 1] c. 1162 – August 18, 1227) was the founder and first Great Khan of the Mongol Empire, which became the largest contiguous empire in history after his death. He came to power by uniting many of the nomadic tribes of Northeast Asia. After founding the Empire and being proclaimed Genghis Khan, he launched the Mongol invasions that conquered most of Eurasia. Campaigns initiated in his lifetime include those against the Qara Khitai, Caucasus, and Khwarazmian, Western Xia and Jin dynasties. These campaigns were often accompanied by large-scale massacres of the civilian populations, especially in the Khwarazmian– and Western Xia–controlled lands. By the end of his life, the Mongol Empire occupied a substantial portion of Central Asia and China.
However, I doubt that you are interested in this mere history. It seems that you are really interested in making sure that your negative opinions of the Catholic Church are stated over and over and over and over and over again. THAT is your interest, it seems.
SO, pax tibi.