The use of archival sources is widely understood to be an important research tool, but the use of archival material is rare in political science, and the material that is used is often misunderstood and misinterpreted so as to make it useless for hypothesis testing. The methodology outlined by this case study was specifically designed and employed in the doctoral researches that led to the compilation of a PhD thesis titled “The Genesis of the Europeanisation of the Northern Ireland Peace Process.” I needed to examine the role of both political and private actors at the supranational level, and in state action at both national and cross-border levels. Accordingly, based on concrete experience, this case sets out the details of the methodology used and the rationale for selection of that methodology. It describes the research design, providing a discussion of the methods used with due recognition given to their weaknesses and gaps, and describes the strategies employed by the researcher to address the issues in question. It concludes by reflecting on how the strategies employed bring history and political science together on a middle ground. Overall, this study outlines a strategy to engage with politics, policies, and political discussions by means of archival research.