In 1988 the Education Reform Act was passed in England. Among its clauses, the one that laid the framework for a centralized, national curriculum represented the most significant change. One of the key aspects of the national curriculum concerned the way in which student achievement and progress were to be measured. Attainment was to be assessed against "attainment targets"; each attainment target would have 10 "statements of attainment" against which the pupil's level of performance could be measured. This paper argues that the new History National Curriculum is based upon a flawed notion of children's historical thinking. The History National Curriculum is based upon the notion that children's historical thinking develops uniformly and progressively through each of the attainment targets and that for each attainment target the nature of this progression can be detailed in a hierarchy of 10 statements. An examination of the statements of attainment is made, and a review of research on children's historical thinking and research on the experience of history teachers in the classroom is carried out. It is argued that frameworks such as those adopted in the History National Curriculum impose a rigidity that limits the possibility for developing the complexity of real historical understanding in students. A list of 61 references is included. (DB)