Historical perspectives reveal how the scholarly field emerged and developed over time and across cultures and how historians of migration have recently begun to re-write the story of human life on earth. Throughout, the authors suggest how the movements of millions of mobile men and women persistently challenge changing scholarly paradigms for understanding their lives. Key concepts and theories, such as systems, networks, and gender, are explained and historicized to produce a complex picture of the interaction of migrants, scholars, and disciplinary cultures in a globalized world.