Secondary school English is shaped not only by complex institutional and discursive forces but also by the mundane reality of available resources. Among the resources used by teachers are commercial textbooks. Classroom textbooks can play a significant role in determining what gets taught in English lessons. They can also influence assumptions about the larger purpose and goals of English. Despite this influence, there have been few recent attempts to analyse rigorously the makeup of English textbooks. This paper describes a method of content analysis that offers a detailed anatomy of the manifest and latent content of English textbooks. We show how the claims of publishers and the rationales offered by textbook authors can be tested against content, activities and design-work in the textbook itself. We also show how a detailed quantitative analysis of textbooks can be used to assess their alignment with official curricula and with prevailing philosophies of English.