Answer: After the unification of the Arab tribes, Islam expanded in all directions. Within a few decades, it occupied an area of land only comparable to the Roman Empire in its heyday. It would soon assume the role of commercial liaison between economically important areas of the world then: in Europe, Africa and Asia. The military progress achieved by the Muslims allowed them to isolate Europe, blocking trade especially through control of the Mediterranean Sea. For many historians, this has accentuated a trend that had existed since the 5th century, focused on agrarian life, and which would lead Europe to feudalism.
The Islam changed because of these encounters, with technology, some traditions and religions were swept away or changed.
That's why we have books. The books some people believe and others just think they are old boring stories.
The First Crusade was highly successful, while the Second was not is correct .
