Abstract In November 1987, the Ashridge Strategic Management Centre was established, with the mission of carrying out research focused on corporate-level strategy and the management of multi-business companies. In November 1997, we ran a major conference to review what we had learned during the last decade. Since Brief Case has reported piecemeal on a variety of the research initiatives that we have carried out during this time, we felt that it would be appropriate to publish the background paper that we prepared for the conference, which gives a brief overview of the main propositions that we believe we have established. We would very much welcome comments on these propositions: Which do you agree or disagree with? Which are most or least important? What areas merit further research and investigation?