Sergio Vieira de Mello, who has died aged 55, after several hours of being trapped in the rubble of his bombed-out office at the United Nations headquarters in Baghdad, was one of the still-rising stars of the UN system.
He was a high-flyer who had handled many of the hardest jobs with distinction and could have become secretary-general.
Urbane, dapper, polyglot, accessible, non-bureaucratic, hard-working and super-smart, he was a walking advertisement for the UN system. His staff members were extraordinarily loyal, and a team of them travelled with him during his last three key posts as the UN administrator of East Timor, then as Geneva-based UN High Commissioner for Human Rights, and on a four-month secondment as the Secretary-General's special representative in Iraq.
Born to a well-off Brazilian family, de Mello seemed destined for an international career after studying at the French lycée in Rio de Janeiro. He went on to the Sorbonne, where he took a degree in philosophy in 1969. He joined the UN High Commissioner for Refugees (UNHCR) as an assistant editor in its publications department but kept open the option of an academic career, earning a PhD at the Sorbonne in 1974.
He moved up the UNHCR ladder, acquiring valuable experience in Bangladesh in 1971, in south Sudan between 1973 and 1974, and in Cyprus after the 1974 Turkish invasion forced hundreds of thousands to flee their homes and divided the island into ethnic blocks. He spent the first two years of Mozambique's independence from the ravages of Portuguese colonial rule in 1975 as the UN's deputy representative in Maputo. Then came two years as UNHCR representative covering northern Latin America.
In Lebanon, he played a key role with the UN team during the period when the current Israeli Prime Minister, Ariel Sharon, was masterminding the invasion of Lebanon as Israeli defence minister and encouraging the massacre of Palestinians in the refugee camps of Sabra and Chatila in southern Beirut. Then came postings in Asia, first as special adviser on the problems of Vietnamese and other Indochinese boat-people and then as director of repatriation in Cambodia.
This range of experience marked him out from country diplomats who function mainly as observers and occasionally as negotiators. De Mello was an activist, on the front line tirelessly helping the victims of war and ethnic conflict as well as mediating in tense situations.
In the mid-1990s de Mello completed his global education by moving back to Europe as the UN's top political officer in Bosnia. In 1999 he reached the coveted level of special representative of the secretary general (SRSG), the equivalent of a UN pro-consul. He was put in charge of the UN administration in Kosovo after Yugoslavia was forced to withdraw its forces and civil administration in the wake of the NATO intervention to reverse Slobodan Milosevic's campaign to drive the Albanian majority out of the province.
De Mello served little more than a month before he was whisked off to take charge of East Timor after the Indonesians agreed to leave the territory they had invaded in 1975. His native language, Portuguese, made him an obvious choice for the job in a place where the elite speaks Portuguese.
But East Timor's gain was Kosovo's loss, and de Mello, in the short time he was in Pristina, had already shown his determination to try to prevent a new wave of ethnic cleansing, this time of the Serb minority. He persuaded key Serb representatives to join a transitional council and also convinced the Albanians that they must accept the right of Serbs to go on living in the province. Although their initial agreement was more in word than deed, de Mello intended to press them to be serious about protecting minority rights - a job he had no chance to continue when he moved to Dili, the Timorese capital, later that year.
His mandate in East Timor was unprecedented for the UN. He was essentially the war-torn territory's governor, exerting powers which no UN official had ever held before.
But, as he was trying to do in Iraq when he died, he saw his primary role as handing the territory back to its people as soon as possible. He brought in an interim government with Timorese ministers, organised elections for a constituent assembly, and then supervised the country's first free and fair presidential elections.
His knowledge of human rights issues made him a natural choice to succeed Mary Robinson as UN High Commissioner for Human Rights. When picked for the Iraq job, he said he would only stay for four months. His primary mission lay in handling the issues of human rights around the world.
Sergio Vieira de Mello: born March 15th, 1948; died August 19th, 2003