‘Humans are a migratory species. Indeed migration is as old as humanity itself’, according to Massey and others (Massey et al, 2009, p 1), reminding readers how humankind spread across the globe from pre-historic times. In the past, as now, people have moved for a variety of reasons, ‘to trade, to study, to travel, for family visits, to practice a skill or profession, to earn hard currency, to experience an alternative culture and way of life and for other reasons too’, as Cohen has similarly pointed out (Cohen, 2006, p 8). And this includes those who have been forced to move, within and across national borders, as asylum-seekers and refugees. This chapter sets out to explore differing ways of defining these movements and explaining these processes, focusing on processes of displacement across national boundaries as well as displacement internally, within nation-states and within world cities in the global North.

Having explored different approaches to migration, including different approaches to women's migration patterns, the chapter focuses more specifically on the notions of diasporas, transnational communities and cultures as these develop across space and time. This sets the context for identifying the range of ways in which communities have defined and redefined themselves and others, within and across borders, transnationally.

Do definitions matter?

The United Nations High Commission for Refugees (UNHCR) argues for the importance of distinguishing between different forms of migration. ‘With almost 60 million people forcibly displaced globally and boat crossings of the Mediterranean in the headlines almost daily’, it was pointed out in August 2015, ‘it is becoming increasingly common to see the terms “refugee” and “migrant” being used interchangeably in media and public discourse’ (UNHCR, 2015). But ‘there is a difference, and it does matter’, this UNHCR Viewpoint continued. The author cited the 1951 Refugee Convention, defining refugees as being in need of protection ‘owing to a well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group or political opinion, is outside the country of his [sic] nationality and is unable to, or owing to such fear, is unwilling to avail himself [sic] of the protection of that country’ (UNHCR, 2015).