Mark Sedwill

Sir Mark Philip Sedwill (born 21 October 1964) is a British diplomat and senior civil servant who has served as Cabinet Secretary and Head of the Civil Service since 2018. He has served as National Security Adviser since 2017. He previously served as the United Kingdom's Ambassador to Afghanistan from 2009 to 2010 and as the NATO Senior Civilian Representative in Afghanistan in 2010. He was the Permanent Secretary at the Home Office from February 2013 to April 2017.