The Roman Empire fell around the 5th century, and as Islam spread in the 7th century, trade between Europe and China slowed. Chinese traders were blocked from westward expansion into Europe when the Chinese army was defeated by Muslim fighters in the area known as Syr Darya. The trade routes, known as the Silk Road, fell into disuse, and trade between the Far East and Europe nearly stopped. It wasn't until the 13th century when the Mongols invaded and controlled central Asia and large parts of the Middle East that extensive trade along these routes was opened again