While looking to revamp his department's Year 7 enquiry on the Tudors, Jack Mills turned to historiographical debates regarding the 'mid-Tudor crisis' to inform his curricular decision making. In doing so, Mills noted that the debate hinged on interpretations of substantive concepts such as 'crisis'. He therefore also drew on previous history-teacher theorisation regarding the types of substantive knowledge students require and its importance for students' immediate and longer-term learning. In this article, Mills outlines how such a focus on historiography and carefully chosen substantive knowledge appeared to manifest themselves in his students' arguments.