AbstractDespite decades of scholarly effort, there is still no universally accepted definition of the concept of minorities or the criteria for minority membership. Beyond its theoretical importance, the lack of a definition also has practical significance, as it may easily lead to the abuse of minority rights. In this paper, we offer a brief historical overview of the various definitional attempts in international law, including those enshrined in legal documents as well as in the practice of adjudicatory bodies. Starting from the era of the League of Nations and the case-law of the Permanent Court of International Justice, we continue by looking at major developments within the United Nations (with special attention to the practice of the Human Rights Committee) as well as the Council of Europe (and the approach of the Advisory Committee of the Framework Convention for National Minorities). Our aim is to explore the trajectory from old to recent conceptual endeavours, where the major dividing line is drawn between the relatively narrow notion of minorities (covering only autochthonous or traditional groups) as opposed to a more inclusive view (including also immigrants and, potentially, visitors under the minority protection mechanisms).