The Crusades resulted in an influx of goods, wealth and knowledge into Western Europe from the Byzantine Empire and the Muslim world. This influx was one of several factors that caused the Renaissance and Europe's shift from being a technological backwater to the most advanced region in the world.
The Crusades began in 1095 and arguably ended in 1291 with the fall of the last Christian stronghold in Acre. During this time, Crusaders brought back foods from the Holy Land such as dates, coffee, rice and sugar, items such as mirrors, carpets and compasses, and ideas such as algebra, irrigation and Arabic numerals. The knowledge of the Romans preserved by the Byzantines and various Muslim rulers spread through trade to Italy and by conquest to other parts of the continent as the Europeans pillaged the lands they visited.