In England and Scotland, the History National Curriculum avoids the prescription of specific content; expecting schools instead to devise a curriculum appropriate to their pupils within broad guidance. This means in both countries, teachers apparently have responsibility for constructing a curriculum: selecting content, sequencing learning and identifying resources, but only in Scotland is it explicitly stated in policy that teachers act as curriculum-makers. Based on the 2021 UK Historical Association survey, this paper explores the extent to which history teachers in England and Scotland use their curricular autonomy to respond to calls for diversified curricula. Drawing on responses from 8% of England's secondary schools and 20% of Scotland's, the data suggest that, although teachers in Scotland are more explicitly framed as curriculum-makers in policy, it is history teachers in English secondary schools who are more likely to have diversified their curricula. The paper explores possible explanations for these findings and suggests that demographic diversity, inspection cultures, and knowledge exchange networks exercise greater influence over teachers' willingness to diversify their curricula than the positioning of teachers in policy.