This article analyzes the common educational challenges faced by curriculum developers in the UK at the turn of the 21st century and the steps taken to address them by the Qualifications and Curriculum Authority in England and the Council for Curriculum Examinations and Assessment in Northern Ireland. The paper explores how the solutions emerging during the three curriculum review phases of 1998-1999 and 2005-2007 in England and 2000-2004 in Northern Ireland came about largely as a result of collegial working between the two bodies. As well as considering steps taken to develop aims that would drive curriculum change and a curriculum that would address the learning needs of students in the 21st century, the article also considers the lessons learnt about managing and supporting curriculum change. Developments in England and Northern Ireland serve to illustrate that an effective curriculum needs to: articulate clearly the key aims that will shape and drive it; be sufficiently visionary and flexible to allow teachers to respond to the needs of students now and in the future; and provide on-going support to help embed and sustain change. The three are inter-related and successful curriculum development involves considering them together.