A demographic revolution is taking place in European cities. In Amsterdam, London, and Brussels, it has already happened, and in Germany, Frankfurt, Augsburg, and Stuttgart are set to follow suit: there is no longer a "majority society" in these places. At the same time, clear ethnic classifications are becoming increasingly difficult, while ambiguities and multiple identities are becoming more important. The English term for this is "superdiversity." Although we have verbally acknowledged the transition to an "immigration society," we have not yet done so mentally, which is crucial: What must be in place for the superdiverse city to function as a community and have a foundation that allows for equal participation and freedom? What is the common ground in a city that consists solely of minorities? Based on the European TIES study, the authors demonstrate that we are at a pivotal moment.