There is an assumption that the ways in which teachers engage with policy are known, yet there is very little evidence to demonstrate how teachers engage with new policies and how this engagement patterns their approach to curriculum development (Kulinna, Brusseau, Cothran, & Tudor-Locke, 2012). Previous research has not clearly distinguished between teachers’ understanding of policy discourses and their subsequent enactment of curriculum. An opportunity to do so arose with the introduction in Scotland of a new curriculum. This new curriculum, Curriculum for Excellence (CfE), intended to provide a framework within which teachers would exercise professional judgment and engage in School Based Curriculum Development (SCBD). The Scottish Government determined the overarching policy for education and Local Authorities were responsible for overseeing the development of the curriculum. CfE intended to empower teachers by encouraging innovation with the proviso that key experiences deemed to be central for pupil learning were addressed. This study aimed to provide insights into the process of SBCD in physical education as teachers prepared for the first year of teaching CfE. The research questions therefore focused on developing an understanding of how the lead teachers tasked with designing the physical education curriculum, within a newly formed curriculum area of health and wellbeing, had engaged with policy and enacted the curriculum. In order to gain a fine-grained understanding of curriculum leaders’ experiences of SBCD, this study drew its sample from a single local authority. The study adopted a research design of repeated interviews with nine teachers who led curriculum development in their respective schools. Two related orders of SBCD as reported and experienced by curriculum leaders emerge from the study: first order SBCD pertains to the process of engagement with policy discourses; and second order refers to the activities associated with the enactment of the curriculum. The findings reported in this thesis showed that events organised by the local authority to support teachers led to the development of a professional learning community which facilitated teachers' active engagement in SBCD. This active engagement required careful tailoring of new developments to the constraints and affordances of their individual schools. First order SBCD was a complex process of engagement/active interpretation and reinterpretation of policy as teachers considered the context for SBCD. These processes led to teachers viewing the broad aims of CfE as a reinforcement of existing practice and curricula. Discourses of accountability appear to have had the most influence in curriculum design decisions, overshadowing the discourses of health and wellbeing within CfE. Teachers’ professional judgements were influenced by regimes of accountability at national and local levels which patterned but did not determine schools’ and teachers’ responses. This is because second order SBCD reflected teachers’ perceptions that a wholescale transformation of physical education was not required or possible within the constraints of their contexts. Curriculum leaders concentrated their efforts on covering the broad aims of CfE and the ‘experiences and outcomes’ outlined in CfE through focusing on their approach to teaching and learning the existing physical education curricula. Thus, they saw health and wellbeing as only one element of physical education rather than as the key focus of their enactment of the curriculum. Teachers’ collective efforts at curriculum enactment were therefore depicted as pragmatic innovation as this encapsulates their responses to policy discourses as they developed a curriculum that would in their view effectively address the broad aims and purposes of CfE while taking account of the constraints of their local context. In contrast to preceding work, a more nuanced account of teacher agency is revealed; teachers were neither wholly the subject of policy discourse nor were they wholly free agents. It follows that if policymakers are seeking transformational change in physical education and an orientation of the subject towards health and wellbeing, there is a need not only for mechanisms to support professional learning, but also for regimes of accountability such as the inspection framework to reflect the policy aims of health and wellbeing more closely.