The introduction presents an overview of the main theoretical questions and debates in the literature on transnationalism and political parties and highlights how these have rarely crossed path. Having stressed this gap in our knowledge, the chapter emphasizes the importance of a better understanding of the growing phenomenon of political parties abroad. We present the research questions that guide the volume: (1) what parties abroad are, (2) when and why do they emerge and develop, (3) how they organize, and (4) what roles do they play. In doing so, we offer to investigate emigrant politics as a new arena for party politics. The introduction also sketches the overall structure of the book and outlines how the various chapters address our research questions and offer a wide range of perspectives on political parties abroad.