What did the expansion of Islam mean for the Europeans who were formerly part of the Roman Empire?

“This assignment is 1-2 pages double-spaced, 12-point. Place your name and course number & section number at the top of the page. Make sure that you place your source(s) for your information at the bottom of the page. (PUT CITATIONS)” What did the expansion of Islam mean for the Europeans who were formerly part of the Roman Empire? What kind of impact did Islam have on the flow of goods east and west and on the Western economy?