The six Gulf Cooperation Council (GCC) countries account for 10.1% of the global migrant population in 2024, making them the world's third largest destination for migrants (UN DESA 2024). The GCC-Asia migration corridor is the largest South-South corridor, and while the Gulf has traditionally drawn workers from the Middle East and South and Southeast Asia, it now also attracts increasing numbers from North and Sub-Saharan Africa. These movements significantly impact societies, economies, and political systems in countries of destination and origin. As integral component of the global migratory system, the ability of Gulf states to attract and retain migrants is a matter of considerable importance for other major migrant-receiving regions as well. Assessing recent and prospects for future migration trends to the Gulf states is therefore crucial. Although research explaining the GCC countries’ status as leading South-South migration destinations is growing, notable gaps remain. This introduction reviews the literature on migration drivers to the Gulf and highlights areas needing further study, before introducing the book’s contributions.