When bigots point to the "wars on religion", they often point to the 30 year war.
Nope, the massacres of the Irish don't count, nor do the Ottoman massacres in Eastern Europe.
But blaming religion as the biggest cause of war even in those days is only "true" if you ignore Asia.
I often cite Professor Bulliet's lecture on the Japanese invasion of Korea causing more casualties than the 30 year war that the western atheists always cite, and now a podcast on a book about the fall of the Ming dynasty also mentions it as one of several conflicts at that time in East Asia. LINK