Seeking to provide a more persuasive and compelling view of the ancestry of what we can define “science diplomacy”, authors in this issue collectively argue for a richer and more nuanced history than the one discussed in the promotional literature. While covering different periods and geographies without being, of course, exhaustive, all articles discusses case studies that shed light on science diplomacy’s role in international affairs, and show how the encounter between scientists and diplomats to promote scientific collaborations has shaped novel transnational power relations that affected knowledge production and circulation.