National Security Adviser, Cabinet Secretary and Head of the Civil Service

Sir Mark Sedwill


Sir Mark Sedwill was appointed Cabinet Secretary and Head of the Civil Service in October 2018.

Sir Mark Sedwill was appointed National Security Adviser in April 2017.

Joining the Foreign and Commonwealth Office in 1989, Mark served in Egypt, Iraq, Pakistan and Cyprus. He was Ambassador to Afghanistan (2009-10), NATO’s Senior Civilian Representative in Afghanistan from (2010-11) and Political Director (2012). He was then Permanent Secretary at the Home Office (2013-17).

Mark was educated at the University of St. Andrews and the University of Oxford. He is married with one daughter.

National Security Adviser

The National Security Adviser is the Secretary of the National Security Council, responsible for ensuring the effective implementation across government of the Council’s direction and guidance.

He is the principal adviser to the Prime Minister and Cabinet on national security strategy, policy, capability and civil contingencies.

He is also the Principal Accounting Officer for the Single Intelligence Account, and the Senior Responsible Owner for the national security cross-government funds.

Cabinet Secretary

The Cabinet Secretary is the Prime Minister’s most senior policy adviser and acts as Secretary to the Cabinet, responsible to all ministers for the running of Cabinet Government.

Head of the Civil Service

The Head of the Civil Service leads nearly half a million public servants who work in public institutions, administer tax, benefits and pensions systems and put government policy into practice. The civil service is a permanent, politically impartial workforce that serves the government of the day, while retaining the flexibility to serve future governments.

Currently civil servants are supporting the government’s economic and public service reform. The scale of the challenges and persistent weaknesses require a reform plan that applies right across the civil service. The Head of the Civil Service is one of several senior civil servants accountable for the reform of the civil service through the Civil Service Board.

Previous roles in government

  1. Permanent Secretary

    • 2013 to 2017
  2. Director General, Political

    • 2012 to 2013
  3. Special Representative on Afghanistan and Pakistan

    • 2011 to 2013


  1. Europe’s security can never be taken for granted: article by Sir Mark Sedwill, UK National Security Advisor
  2. "We aim not only to tackle the symptoms, but also the root causes of terrorism."