Kofi Anan, the former secretary general for the United Nations and Ghanian diplomat, has passed away at age 80. Annan served two terms as the secretary general, between 1997 and 2006, and his time at the United Nations brought a renewed sense of hope for the power of international law.

“Born in Kumasi, Ghana, on 8 April 1938, Annan joined the UN system in 1962 as an administrative officer with the World Health Organization in Geneva. Annan later served with the Economic Commission for Africa in Addis Ababa, the UN Emergency Force in Ismailia, the UN high commissioner for refugees in Geneva and in several senior posts at its headquarters in New York,” the Guardian reports. “Before becoming secretary general, he was under-secretary general for peacekeeping and also served as special representative of the secretary-general to the former Yugoslavia between 1995 and 1996.”

Though he is best known for his work at the United Nations, it was far from his only role. He was chair of The Elders, a group of global leaders founded by Nelson Mandela who work toward peace and human rights. In 2001 he and the UN were awarded the Nobel Peace Prize for their peacekeeping and humanitarian work. Annan felt a deep tie to his roots in Ghana and a responsibility to the region. He was also a man of grace, a man of wit and of humour, and even a man who was good-natured enough to sign an autograph when he was mistaken for Morgan Freeman.

Despite the criticism the UN is often under, Annan remained not only its greatest and most persuasive figurehead, but also its biggest defender. “The UN can be improved, it is not perfect but if it didn’t exist you would have to create it. I am a stubborn optimist, I was born an optimist and will remain an optimist,” he told the BBC in April of this year, during his final interview with them.

Even with his optimism, he was not afraid to be critical when it was needed. One of his most lasting comments came during a speech at the Harry Truman presidential library in Independence, Missouri. In an unsubtle jab at President George W Bush, Annan said, “When power, especially military force, is used, the world will consider it legitimate only when convinced that it is being used for the right purpose – for broadly shared aims in accordance with broadly accepted norms.” He voiced the concerns of the international community — and the world agreed.

He’s a person who undeniably left the world in a better state than when he came into it — who brought more light and peace and hope. And he did so with a huge amount of self-awareness of how the world viewed his optimistic, humanitarian approach to international politics. When asked what people thought of him and the UN, his answer was incredibly revealing. “That he’s too soft,” he once told the Guardian. “Because they feel he doesn’t pound the table – not assertive enough. But it doesn’t bother me, because sometimes you don’t have to fight to get your way. You don’t have to pick a fight to get them to change their mind, or get them to see things your way. You really don’t.”