Elizabeth Wilmshurst had a distinguished 29-year Whitehall career
Former Foreign Office legal adviser Elizabeth Wilmshurst was the only civil servant to resign in protest at the decision to go to war in Iraq.
Ms Wilmshurst, now a fellow of the Royal Institute of International Affairs at Chatham House, resigned in March 2003 before the first attacks on Baghdad.
She told her superiors that an invasion of the country without UN sanction would be a "crime of aggression" before stepping down from her post as deputy legal adviser to the Foreign Secretary.
, Ms Wilmshurst said she could not agree with the decision to go to war "in circumstances which are so detrimental to the international order and the rule of law".
The letter was was released by the Foreign Office, under the Freedom of Information Act, two years after her resignation.
Ms Wilmshurst is considered to be one of the UK's leading experts on international criminal and diplomatic law.
With a 29-year Whitehall career behind her, the lawyer had been a trusted stalwart in the corridors of power.
One of the Foreign and Commonwealth Office's senior legal minds, her service was rewarded with a medal. In 1998 she was made a Companion of St Michael and St George (CMG).
The CMG is one of the highest honours that can be bestowed on a diplomat. It is awarded to those in high office or people who render extraordinary or important non-military service abroad.
But Ms Wilmshurst's views on the Iraq invasion later found her at loggerheads with the government.
In an interview with The Independent after her resignation, she issued a damning critique of the coalition's campaign.
She told the newspaper "it could be alleged that the use of force in Iraq was aggression", and that "the kinds of abusive treatment of Iraqi prisoners that have been alleged could amount to war crimes".
Her legal career began after she left Clarendon School, in north Wales, and studied at King's College, London.
After completing her law degree, she was admitted as a solicitor in 1972 and worked as an assistant lecturer at Bristol University.
Ms Wilmshurst's Whitehall career began in 1974.
A role as assistant legal adviser led to her gaining the post of legal counsellor, both at the Foreign and Commonwealth Office, before moving to become assistant legal adviser, and later legal counsellor, at the Attorney General's Office.
She returned to the Foreign and Commonwealth Office in 1990 as legal counsellor.
The lawyer maintained the same role at the United Kingdom Mission to the United Nations, New York, before going on to become deputy legal adviser at the Foreign and Commonwealth Office in 1999.
Ms Wilmshurst now combines her commitments at the Royal Institute of International Affairs in London with her role as a visiting professor at University College London.