Jews were an ethnic group (with its own "national" religion - Judaism; and its own sacred language - Hebrew), who - after settling in various regions of Medieval Europe - became a social class (in European Feudal social order), because they occupied a certain economic niche and engaged only in certain professions, while not engaging in other professions. For example - there were hardly any Jewish farmers (peasants), which distinguished them from nearly all other European ethnic groups - in which majority of people were peasants and engaged in farming.