"Christianity did not take 1100 years to discover violence by any measure. Read Dark Ages history and see how many tribes were converted because their leaders were defeated in battle, and the conversion was part of the settlement. I cannot say that I see Christianity as a religion of peace until 1100, nor can I excuse what it during the Crusades based on not having access to a given piece of property that had historically had belonged to the Jews."
Now, being the snarky and well-read sort of amateur historian that I am, I wondered what sort of history this person had been reading. Perhaps Wiccan history, about 'peaceful Earth religions' in pre-Roman Gaul and the "Burning Times".
Now, I recall that Chucky of the Magnificent Ego (King of the Franks, no matter what title the Bishop of Rome handed him) tried to mandate that the defeated Saxons convert to Christianity, and I know that the Teutonic Order in the 13th century fought pagan Baltic tribes, but I'm trying to think of other examples and failing.
I'm also baffled as to what crack the person is smoking regarding the Roman province of Palestina, which was part of the (Christian) Roman Empire for centuries before the Muslims conquered it. Even then, it wasn't until the Seljuks started murdering pilgrims and invading Anatolia that the Crusades kicked off.
I note that the person has not responded to my request to cite source or retract.