This paper first offers a brief excursus on the main factors that have conditioned the development of the modern Greek state and the dominant conception of Greek national identity. The second part of the paper concentrates on the internal Significant Others (Triandafyllidou, 1998) of Greek society over the past 30 years with a view to identifying which have been the important minority groups that have challenged with their diversity the reputed cohesion and homogeneity of Greek society during the last three decades. We cover three distinct time periods: the 1980s and the end of the Cold War, the 1990s and the rise of multiculturalism in Western Europe but also the debacle of Communist regimes and the subsequent transition of central Eastern Europe to liberal democracy, and the last decade with the expansion of the EU to the east, the rise of international terrorism, the financial and economic crisis and the contest of multiculturalism (in Western Europe) in the last couple of years. In the second part we shall seek to highlight the aspects of ‘difference’ of specific groups that have been particularly contested. Those aspects that the groups advocate as important for their identity and that the state or the majority group consider ‘intolerable’ or at least difficult to accommodate. Pointing to such challenging differences will help locate different instances in which ‘tolerance’ has been an important concept or practice with a view to allowing for diversity to exist. Naturally we shall also take note of the competing concepts in favour of a more active accommodation and respect for diversity or concepts and behaviours that call for the rejection of diversity and the imposition of not only unity but also homogeneity within Greek society.