This work deals with the Mongol people who visited or permanently settled in Europe during the Mongol period. This article will examine in detail the purpose for which the Mongols came to the European world, what types of people came, and whether they came temporarily or settled permanently. There were two main categories of Mongols who visited Europe or finally settled in Europe during the period of the Mongol Empire. One was diplomatic envoys, the other was slaves who were forcibly brought to Europe. The Mongols visited Europe for military cooperation or were forcibly brought into Western Europe as slaves, while the Europeans went to the Mongol realm mainly for commerce, evangelical propagation, and military alliances against Islam. This work also deals with the perceptions and attitudes of medieval European Christians toward the Mongols. European perceptions of the Mongols as strangers were negative overall. Of course, the perceptions of the Mongols changed depending on the period and historical contexts. For example, in the late 13th century when Europe and the Ilkhanate sought the possibility of military cooperation to defeat the Mamluk Empire, Western Europe’s perceptions of the Mongols were favorable, even if temporarily. However, this military cooperation did not take place, and fear and hatred of the Mongols continued in the 14th century.This study will fill the gaps in previous research that has been mainly focused on the activities of Europeans who entered Asia and provide a comprehensive understanding of exchanges and contacts between East and West during the Mongol period. In fact, Europe had already secured considerable information about Asia and Asian people through exchanges and contacts with Asians represented by the Mongols before the Age of Discovery. In the end, this article aims to review the previous interpretation that Europe and Asia first made contact as Vasco da Gama and Christopher Columbus opened new routes in the late 15th century.