There have been eight secretaries-general of the United Nations in the 68 years since the first of them, Trygve Lie of Norway, took on this unique global position. All eight — all men — have been very different in character and personality, in their cultural and political backgrounds and in their views of how the job should be done. Yet there is a continuum, as each secretary-general inherits the legacies of his predecessors and must take them into account while shaping the role anew.

Lucia Mouat, a former correspondent at the UN for the Christian Science Monitor, tells their stories in a new book likely to become a standard reference on the subject. The book, “The United Nations’ Top Job: A Close Look at the Work of Eight Secretaries-General,” keeps its focus on these office-holders through years of crises, wars and fundamental changes within the institution and the world. The secretaries-general were, and are, always in the center of global affairs to one extent or another, often trying to help shape events or lower tensions, while always feeling the pressures of governments. A lot of this is never seen by the general public anywhere.

From the beginning, there was not much common agreement on what powers a secretary-general would have. The UN Charter was little help. “In the end, the UN Charter says little about the UN’s chief role and its limits,” Mouat wrote, adding that the drafters were clear only that a secretary-general was to be the organization’s chief administrative officer and the person responsible for carrying out Security Council decisions. At the start, the author said, “the major powers believed they would run the United Nations together. They thought they needed an office manager rather than a policy maker.”

Since the founding of the UN, the secretaries-general have come, in chronological order, from Norway, Sweden, Burma, Austria, Peru, Egypt, Ghana and (south) Korea. Unofficially, the job is expected to rotate around regions of the world, often a cause of considerable contention and disagreement among subregions or smaller nations that feel they have been systematically shut out. By tacit agreement among the five permanent members of the Security Council — China, France, Russia, the United Kingdom and the United States — the citizens of all these countries may not be candidates for the position.

Trygve Lie, the Norwegian lawyer and foreign minister, didn’t want the amorphous job initially and had to be talked into taking it; he preferred the presidency of the General Assembly. He was also not the first choice of numerous nations, including the US. Russia, however, pushed his candidacy for secretary-general, and he was chosen in a compromise.

Mouat quotes Brian Urquhart, whose long, exemplary career in UN service included working as one of Lie’s personal assistants and advisers. “There was no consideration of who might be best qualified for the job,” Urquhart told the author in an interview, one of many valuable and archival conversations recorded in this book. Mouat noted that Urquhart saw how the choice of Lie “illustrated the limits that the increasingly adversarial East-West relationship was placing on UN effectiveness.” The ingredients for stalemate are still echoing in Russia’s standoff and confrontation with the US and Western Europe over Syria and Ukraine.

Additional tension has in recent decades been put into the mix by the growing strength of emerging powers and other developing nations of the global South, who repeatedly call for greater influence in the UN, particularly in the Security Council.

Lie, the son of a carpenter and former labor union lawyer, could not have been more different that his successor, Dag Hammarskjold, a Swedish aristocrat who once lived in a castle and whose father became the country’s prime minister. He is probably best remembered of all early secretaries-general for his intellectual writings (which some call mystical) and for his untimely death in a plane crash in Africa in 1961 while on a mission to deal with conflict and secession in Congo. The Democratic Republic of the Congo remains one of the UN’s perpetual challenges.

“He was a shy, quiet, awkward intellectual who was spectacularly bad at dealing with people,” said Urquhart, who had a close relationship with Hammarskjold as the UN’s role in peacekeeping was being established. “But the most amazing thing about him was that you could go to Rio, New Delhi or Cape Town and the taxi driver would have heard of him and have an astonishingly clear idea of what he was trying to do.”

U Thant, the first and only Asian before Ban Ki-moon to hold the position, walked straight into a series of international conflicts during his decade in office: the continuing Katanga secession issue in Congo, the Cuban missile crisis, war in Kashmir, the six-day Arab-Israeli war and the building Vietnam conflict. A nonconfrontational man, Thant plunged into mediation on several fronts and incurred the wrath of several nations, including the US, before his term ended.

With Kurt Waldheim, Mouat gets to what might be considered the contemporary era, in that Waldheim, an ambitious Austrian politician, was the first candidate for UN secretary-general to openly campaign for the job — and the first to try to seek a third term in office. Since then, candidates have been more open about their candidacies, though vetting of aspirants still does not take place in any organized, open way, and campaigns have been conducted mostly behind the scenes with governments in capitals or in regional horse-trading sessions.

The Middle East and western Asia consumed most of Waldheim’s energies during his two terms as secretary-general. The American hostage crisis in Iran, a Turkish-Greek confrontation in Cyprus, another Israeli-Arab war, the Soviet invasion of Afghanistan and the long conflict between Iraq and Iran marked those years. It was also during that period that the “Zionism is racism” resolution was passed with a wide margin in the General Assembly, driving American relations with the UN to a very low point.

To the chagrin and embarrassment of countries that had supported Waldheim’s tenure at the UN, it was later revealed that he had been a member of a Nazi youth group in Austria and, after 1938, a trooper and officer in Hitler’s army. This record had not emerged during his candidacy for the UN’s top job, or it had been covered up by his own lies about his background. That did not stop him, however, from becoming president of Austria in 1986.

Javier Pérez de Cuéllar, who followed Waldheim, was another compromise choice in the Security Council, which effectively chooses a secretary-general, who is then confirmed by the General Assembly. Pérez de Cuéllar, a career diplomat and  cosmopolitan who chose not to campaign for the job, cultivated his reputation as an impartial mediator who was unfailingly polite and also not confrontational. He once acknowledged that he knew he was not “an exciting choice” for the job.

Although not the best of administrators, he gained wide respect for his attention to working closely with the Security Council while offering his services in mediating, successfully, an end to prolonged fighting such as the Iran-Iraq war and the conflicts in Central America in the 1980s.

“Pérez de Cuéllar . . . launched an important new approach to the council,” Mouat wrote. “He tried to attend every council meeting, something his predecessors had not done.” He also understood, various former officials told her, the limits of what he could do as secretary-general and the barriers to action sometimes faced by a divided Security Council. He knew there were separate but complementary roles for both in the power structure. The US liked him enough to ask if he would consider staying on for a third term. He declined, politely.

Boutros Boutros-Ghali, an Egyptian who had played a major role in attempts to negotiate agreements between Israelis and Arabs, was to suffer a different fate at the hands of Washington. Publicly, he was pilloried for not stopping the vicious wars in the Balkans after the breakup of Yugoslavia and for not intervening to prevent or stop genocide in Rwanda, both unfair accusations when the reluctance and parsimony of the Security Council, especially the US, made inadequate decisions on intervention and resources were not authorized to meet the tasks.

When the secretary-general (and his unusual name) became a butt of crude humor and contempt among provincial Republican members of Congress, some of whom bizarrely also accused him of trying to subvert American sovereignty with UN troops, the administration of President Bill Clinton, running scared of the political opposition, denied him a second term in the most humiliating way. It was a disgraceful move.

The US quickly moved to put Kofi Annan, a seasoned UN official and former head of peacekeeping into office, though not without an unseemly marginal squabble with France over whether his French was good enough to head a theoretically bilingual organization. Annan soon became known as a leading advocate for human rights and for commissioning a series of reports on the future work of the UN, including in peacekeeping, that have formed the base and touchstone of international policy debate and decisions in the organization ever since.

Annan, who with the UN won the 2001 Nobel Peace Prize, also faced hostility in the US. He publicly opposed the American-led invasion of Iraq in 2003 and became the target of American conservatives who accused him of being responsible for illegalities in oil sales by Iraq under a program designed to aid Iraqi civilians living under sanctions. What became know as the “oil for food” scandal proved to have involved a host of governments and companies (some of them American) who had been dealing illegally with the Saddam Hussein regime. Annan himself was chided only for poor management of a program that ran pretty much independently of his office.

The final words on the Ban Ki-moon era will have to wait to be written, but Mouat noted his commitment to dealing with climate change as a priority he set himself from the start of his first term. That has been a tough sell, but he is still at it. He travels exhaustively — and is criticized for spending too much time on the road. But his approach, from the early days of his campaign to be elected secretary-general, has been face-to-face meetings with all people who need to be brought into discussion on issues, from leaders of governments to peacekeeping missions and humanitarian agencies working in the many fields of UN assistance. He meets local people and assesses situations personally.

Ban has been able to persuade Sudan’s president to accept joint UN-African peacekeeping troops in troubled areas, to convince an Ivory Coast president to accept election defeat and to persuade the Burmese military leadership to open the country to humanitarian aid after a powerful cyclone and extend that cautious opening to political change. If Ban rarely makes headlines, it may be because he doesn’t seek them.

Barbara Crossette

Barbara Crossette is the senior consulting editor and writer for PassBlue and the United Nations correspondent for The Nation. She is also a member of the Council on Foreign Relations. She has also contributed to the Oxford Handbook on the United Nations.

Previously, Crossette was the UN bureau chief for The New York Times from 1994 to 2001 and previously its chief correspondent in Southeast Asia and South Asia. She is the author of “So Close to Heaven: The Vanishing Buddhist Kingdoms of the Himalayas,” “The Great Hill Stations of Asia” and a Foreign Policy Association study, “India Changes Course,” in the Foreign Policy Association’s “Great Decisions 2015.”

Crossette won the George Polk award for her coverage in India of the assassination of Rajiv Gandhi in 1991 and the 2010 Shorenstein Prize for her writing on Asia.