Mr Sergio Vieira de Mello, the top United Nations envoy to Iraq who was killed by this afternoon's bomb blast in Baghdad, was a tough but debonair Brazilian who had been dispatched on some of the world body's most difficult missions.
Mr Vieira de Mello, 55, was trapped under rubble and died after the suspected suicide bomb blast.
The UN High Commissioner for Human Rights since September last year, Mr Vieira de Mello was the immediate choice of Secretary-General Mr Kofi Annan to take on the Iraq job in May after the controversial US-British invasion to oust Saddam Hussein.
He was also the US choice and had been summoned in Marchto Washington, weeks before the start of the US-led invasion to be sounded out by President George W Bush.
But Mr Vieira de Mello insisted his Iraq assignment be for just four months so he could hold on to his UNHCHR post.
After arriving in Baghdad, he had quickly established his presence and won the respect of the US-nominated Iraq administrator Mr Paul Bremer, despite tension between Washington and the UN Secretariat over the Iraq war.
"The relationship has been businesslike, it has been constructive, and it has been frank," Vieira de Mello, 55, told reporters in Cairo last week. But he agreed he had landed in "a delicate.....and even bizarre situation" in post-war Iraq.
In an address to the UN Security Council in July, he made what was to be a prescient remark, saying: "The United Nations presence in Iraq remains vulnerable to any who would seek to target our Organisation."
Mr Vieira de Mello, born in Rio de Janeiro, had worked for the United Nations for 35 years, starting as a junior publications editor with the UNHCR refugee agency in Geneva in 1969. He was no stranger to danger -- or to the problems of rebuilding countries shattered by war.
For over two decades with the UNHCR and on secondment, he served as a field officer in a devastated Bangladesh after its war of separation from Pakistan, and in civil war zones in Sudan, Mozambique and Lebanon.
Moving up through the ranks of the UNHCR, he was consigned to desk jobs running relief operations from Geneva during much of the 1980s - including crises in the Great Lakes region of central Africa and the exodus of Albanians from the country after the collapse of communism in 1991.
In 1993, he was dispatched to Bosnia and took charge of civil affairs for the U.N. Protection Force, and in 1996 became Assistant High Commissioner for Refugees.
Two years later, Mr Annan took him to New York to become Under-Secretary General for Humanitarian Affairs and then sent him briefly to the Serbian province of Kosovo before giving him his biggest task - building the new Asian nation of East Timor.
Mr Vieira de Mello played a vital role in bringing East Timor it to full independence by 2002.In September last year Mr Annan named him - to acclaim from campaigning non-governmental groups (NGOs) - UN human rights chief to replace former Irish President Ms Mary Robinson.