One of the main reasons why the Islamic world suffered hardship during the 1200s and 1300s was because "<span>d. Western European kings sent armies to retake Jerusalem and capture as many Muslims as possible to use as slaves," since this was the time of the "Crusades". </span>
Explanation: LAW
The necessity of fighting off invading groups was one aspect of the Roman Empire that continued into the Byzantine Empire. The Byzantine Empire, a very powerful and vast civilisation, emerged after the Roman Empire during Late Antiquity and the Middle Ages. Constantinople became its capital.
I believe its <span>William Harry McRaven but im not 100 percent sure</span>