This paper explores the challenges for teachers in positioning them as independent curriculum makers. History teachers in New Zealand have recently entered uncharted territory with the abandonment of prescribed topics for history and a new-found authority to determine the selection of historical knowledge taught to their senior secondary students. This paper examines the complex nature of the teacher's new role and responsibilities and argues that curriculum achievement objectives and national assessment places significant constraints upon teachers' selections of historical knowledge. There is the potential for substantive historical knowledge to be downplayed in favour of procedural knowledge and the potential for assessment drivers to dominate or distort selection of knowledge for history. Local curriculum making places a heavy burden of responsibility upon teachers with implications for students' access to powerful historical knowledge.