Markers of identity define human groups: who belongs and who is excluded. These markers are often overt — language, material culture, patterns of behaviour — and are carefully nurtured between generations; other times they can be invisible, intangible, or unconscious. Such markers of identity also travel, and can be curated, distilled, or reworked in new lands and in new cultural environments. It has always been thus: markers of identity are often central to the ties that bind dispersed, diasporic communities across lands and through time. This book brings together research that discusses a very wide range of scholarly approaches, periods, and places — from the Viking diaspora in the north Atlantic, and Anglo-Saxon treasure hoards, to what DNA can and cannot reveal about human identity, to modern, multicultural Martinique, East London, and urban Africa, and the effect of the absence of geopolitical identity, of statelessness, among the Roma and Palestinians — to better understand how markers of identity contribute to the impact of diasporas. This book was originally published as a special issue of Ethnic and Racial Studies.