After graduating from Oxford and the University of Tübingen, West Germany, Stephen worked for The Boston Consulting Group for a total of seventeen years before subsequently joining the Ashridge Strategic Management Centre in 2001.

He teaches on several executive programmes at Ashridge Business School, Judge Business School in Cambridge and the European School of Management and Technology in Berlin, and is a regular guest speaker at the UK Defence Academy.  He also works as an independent consultant and is in high demand as a conference speaker.

He has spent several years working on the subject of strategy execution and his resulting book The Art of Action – How Leaders Close the Gaps between Plans, Actions and Results was published by Nicolas Brealey in November 2010.  It was shortlisted for the CMI Management Book of the Year Award 2011.
Some of the key concepts of the book, such as the ‘three gaps’ model, are coming into increasing use in companies and being cited by others.  His concept of the ‘executive’s trinity’ was the theme of a major HR conference held in Berlin in October 2014.

He published his first book on military history, The Most Dangerous Enemy – A History of the Battle of Britain, in 2000.  It has now become the standard work on the subject.  A second work, Alamein, appeared in 2002.

Since 2004 he has also been a frequent contributor to television programmes, including the Channel 4 series ‘Spitfire Ace’ and BBC 1’s ‘The Real Battle of Britain’ which was screened in September 2010.  His most recent appearance was in ABC’s two-part documentary about the desert war.