Portugal is a small European country located in the western part of the Iberian Peninsula with stable geographical mainland boundaries since the thirteenth century. One of the leaders of European overseas expansion during the sixteenth century, Portugal declined after 1600 while northern European states took the leadership. From the eighteenth century onwards, despite securing a large empire that included Brazil and a significant share of African territories, Portugal shifted from a center to a periphery. This particular, and even paradoxical, trajectory, from a European center to a periphery, but still keeping its centrality concerning its long-lasting empire in Africa (the last Portuguese colonies became independent in 1975), places Portugal as a privileged case study to look at the role played by science, technology, and medicine (for short science) at the national, transnational, and global levels as well as in a long-durée perspective.