EDINBURGH – Kofi Annan will be mourned on every continent. Under his leadership of the United Nations, internationally shared goals for development (the Millennium Development Goals) were agreed for the first time. But there were other important firsts that occurred on Annan’s watch: The Global Fund to Fight AIDS, Tuberculosis, and Malaria was created; $100 billion of African debt was forgiven; aid to the poorest countries rose fast; the Responsibility to Protect principle moved from one man’s aspiration to unanimous endorsement by the United Nations General Assembly; and the first steps toward the Paris climate agreement were taken.

These were just a few of the causes that Annan championed. His achievements confound those who write off the UN as a mere talking shop.

I remember attending, at his invitation, a meeting of the Kofi Annan Foundation in Geneva and discovering how in his retirement he was advising, in one way or another, a half-dozen countries in Asia, one or two in Latin America, and the majority of countries of Africa on human rights, elections, or poverty alleviation. For that reason, no single assessment can do justice to the breadth and depth of the successes of a leader who brought the UN’s decision-making out of smoke-filled rooms and into the twenty-first century.

Each advance made during Annan’s ten years as Secretary-General owed everything to his personal commitment, determination, and faith in the future. And it is a tribute to the moral force of his vision that he made progress at a time when the Security Council was split on almost every major issue – as on Iraq – and the UN’s major financier, the United States, did not view him with affection.

Soft spoken, personally modest, gentle, and almost self-effacing, Annan was both a UN insider, promoted from within the organization’s ranks to be the first African to hold the office of Secretary-General, and an anti-establishment campaigner who galvanized and mobilized the international NGO community to force change on often-reluctant states.

Of course, the new global order he sought has been long delayed by great-power rivalries, nationalism, and protectionism. Despite his good intentions, the UN failed to prevent the genocide in Rwanda before he became Secretary-General, as well as the wars in Bosnia, Iraq, and, more recently, Syria, where for a time he was a peace envoy. But even when it came to peacemaking, he was more than a witness to history. His charisma made him friends everywhere, and his patience rivaled that of a saint. Despite setbacks and disappointments, he persevered, and ultimately changed our view of what international cooperation could make possible.

Supported in his Foundation’s work by his wonderful wife Nane, Annan continued to champion, in his retirement, the environmental, democratic, and anti-poverty causes he had made his life’s work – and he never gave up. I recall working with him ten years ago as he labored night and day to bring together both sides after Kenya’s disputed presidential election and post-election ethnic violence. Annan’s mediation undoubtedly prevented the loss of more lives.

In the last few months, I talked with Annan about Myanmar and the pathbreaking proposals put forth by his Advisory Commission on Rakhine State, which, even now, offer the best chance of reconciliation and an end to the crisis that has been destroying lives in that strife-torn country. He loyally supported the international work to fill a gap in the global architecture for development, by backing the Education Commission’s plan – along the lines of The Global Fund – to create a $10 billion International Finance Facility for Education to achieve the Sustainable Development Goal on universal education.

Even in the last few months of his life, Annan was, as ever, active and available to help – advising on the elections in Zimbabwe, championing youth leadership with his program to inspire a new generation of internationalists, and calling for more attention to human rights and democracy through the recent reports and conferences run by his foundation.

Annan’s journey is over. But the legacy of this leader of leaders will live on in the impact his work continues to have on the lives of people on every continent.

Gordon Brown, former Prime Minister and Chancellor of the Exchequer of the United Kingdom, is United Nations Special Envoy for Global Education and Chair of the International Commission on Financing Global Education Opportunity. He chairs the Advisory Board of the Catalyst Foundation.