Crusades? Try 312 AD.
A bit of a head start, there, eh? Doing the exact same thing to what later became the Islamic lands, namely, forcing Christianity by force on all in their path. Remember, what we call the Middle East and North Africa plus Southern Europe were THE Europe, the Roman Empire, ages before the people of the northern hinterlands were ever discovered. That land was all the original Christendom. All of it. And it was all done by force.
Yet you talking about Islam doing the exact same thing in the name of the same exact God somehow didn't ring any bells about their own origins, which, in case no bells were ringing again, was Christianity. If it wasn't for Christianity, there never would have been Islam.
But still, does three centuries ahead explain how Christianity has in 2,000 years killed more people on planet Earth than all other religions, ideologies, countries, peoples, ethnicities, races, continents, you name it... Combined? COMBINED?
Granted, Harry President Harry S Truman put an end to that endless massacre fest when he decided to domesticate the rest of the planet after it lost WWII to America. But just because Christians stopped the wholesale slaughter of the rest of humanity a whopping half a century ago doesn't mean it never happened. It happened. And there are still quite a lot of people alive today who were alive then when it was happening.
Killed more people than all others combined. Christianity. Combined. Combined.