Stephen became Permanent Secretary for the Ministry of Defence (MOD) in April 2016. Prior to MOD he was Permanent Secretary for Department of Energy & Climate Change.

Stephen spent 9 years at the Shareholder Executive and was appointed Chief Executive in June 2007. Before that he spent 10 years at Deutsche Bank, where he was the head of the European media team working on a wide range of capital raisings, acquisitions and divestments in all the sub-sectors of the media industry.