This paper reports a Critical Discourse Analysis (CDA) exploring the nature, causes and epistemic effects of knowledge recontextualization in the 'official' Key Stage Five History curriculum in England. "Recontextualization" refers to inevitable changes that occur to knowledge as it is 'pedagogized', due to the value-laden practices and contexts which enact and shape curriculum-making. Five accredited examination specifications and three 'generative' policy documents were analysed using Fairclough's methods and interpreted through a Bernsteinian theoretic lens. Five problematic forms of knowledge recontextualization will be discussed: canonization; commodification; de-diversification; knowledge made static; and epistemic inconsistency. The application of CDA to everyday 'official' curriculum artefacts illuminates the role of micro-level 'language-in use' in bringing particular constructions of subject knowledge into being. It is suggested that not all these recontextualizations were intentional, nor fully explainable through macro and meso structural factors. Some had been enacted 'by accident' in the contingencies of fragmented and negotiated local practice. Epistemic and discursive 'literacies' are suggested as key to engendering agentic practice within the official curriculum-making community, as well as enabling teachers to select and pedagogically mediate specifications in line with local epistemic aims.