Sahel is a very desert like area. It is hot but not as humid as a rain forest would be because of the lack of water.
European leaders responded to Islamic expansion in a very violent way. Following the initial incursions of the Islamic forces in those years, the European leaders decided it was time to take up arms and fight them in their own lands - what followed were the Crusades.
It’s the first one because Islam’s the only religion that believes Muhammad was the,elder of their religion and Judaism believes that Jesus is the 1 that led them to their religion. They believe in different leaders