This video may seem rather dry. But it gives the background leading up to the resistance which led to the Crusades themselves. Charles Martel was a game-changing personage in Christian history.
I am aware that there are Islamic teachings which lead to a more peaceful application of that faith. I think that the interpretation referenced here is an accurate depiction of of the application of Islamic teachings in 633-638 AD. It also seems that it is still relevant to Islamic extremists today.
I want to emphasize that this video discusses events which happened almost 1400 years ago. The reason I am posting it here is to correct the inaccurate history of the Crusades which is being used in the popular media to attack and degrade Christians and Christianity.