My actual JOB is to teach history. I’m a professor at a private college in central Alabama. I teach just about every subject there is, including ancient history, world history, Western civilization, and American history. I can definitively tell you that you CANNOT learn about world history without learning the history of the Catholic Church. Without Catholicism, there is no Constantine, no hospitals, no monasteries, no universities, no scholasticism or summas, (heck, no Western Europe to speak of…), no Byzantine Empire, no Islam (since it is a progression from Catholicism), and a HUGE decrease in the amount of religious monuments, cathedrals, and works of art and music. Without understanding the Catholic Church, you cannot understand the Crusades. You cannot understand the Reformation. You cannot even understand where your OWN denomination came from, and what it was “protesting” that caused it to form in the first place! Ask ANY professor what THREE institutions all Western Civ students MUST know about, and they’ll say ancient Greece, ancient Rome, and the Catholic Church. It’s just that important, and I’m not talking even from a religious viewpoint. I’m talking from an HISTORICAL viewpoint.
And since you’re also interested in military history, without the Catholic Church, there’d be no Hundred Years’ War, no Joan of Arc, no Thirty Years’ War, no Richard the Lionhearted, no Battles of Tours, Lepanto, and Vienna to save Europe from Muslim invasion, no Greek Fire, no El Cid, no knights (of ANY kind), no Reconquista, no discovery of America, no missionaries to the New World and defense for Native Americans, and so on.