Improving numeracy learning outcomes for students is a goal of the European Commission. While many European countries have placed increased emphasis on links between mathematics and other subjects, in some countries numeracy is seen as an integral part of subjects across the curriculum. However, for this latter approach to be successful teachers need to have the capacity to embed numeracy into the subjects they teach. This article builds on previous research where it was suggested that teacher identity could be used to identify ways to support teachers to embed numeracy in subjects across the curriculum and that an adaptation of Valsiner's zone theory could be used to understand this identity. The purpose of this article is to use the detailed case study of a secondary school history teacher to explore how the theoretically developed framework for identity as an embedder-of-numeracy plays out in an empirical study. The analysis permits suggestions to be made about ways this teacher could be supported to embed numeracy in history and points to areas for further research.