This introduction highlights the analytical potential of “belonging” for those studying the social processes of Jewish exclusion in the Holocaust. It does so by proposing a tripartite definition of “belonging,” one that bridges emotions, everyday practices, and generational memory. Offering a close reading of diaries, memoirs, memorial books, testimonies, trial records, oral interviews, and individual and group chronicles, articles included in this special section capture the experiences of those who have been rejected from historically multiethnic and multireligious communities and the ways in which this process took place at the time and was narrated later. By examining physical and symbolic encounters between individuals and groups, we show how those at the margins negotiated and expressed their changing place in the broader community, how they interpreted and appropriated social engineering by the regime, and how they responded to their categorization by neighbors and the authorities which ultimately marked them for murder. The advantage of this approach lies in inviting and enabling comparison, and in its relevance for individuals and groups that were either included in or excluded from the locally redrawn categories of “national communities.”