It's Not About the Crusades- CT

In addition, Western Christians feel deep guilt over the Crusades, even though, as Sanneh says, Arab historians give the Crusades (which they refer to as the wars with the Franks) little notice. These incursions, mostly rebuffed by the Muslims, pale in comparison to the Mongol invasion under Genghis Khan.

Sanneh urges Western Christians to move beyond the guilt of the past. The global picture has changed, after all. Although the worldwide percentage of Christians has declined only slightly, from 35 percent in 1800 to 33 percent today, the geographical shift has been immense. While Christianity lost 800 million adherents in the 20th century—mostly in Europe and the former Soviet Union—explosive growth in places like Africa and China replaced them. (Sanneh acknowledges that this explosive growth occurred only after colonialism ended.)- Philip Yancey