Javier Perez de Cuellar, the two-term United Nations secretary-general who brokered a historic ceasefire between Iran and Iraq in 1988 and in later life came out of retirement to help re-establish democracy in his Peruvian homeland, died on Wednesday at the age of 100, Peru’s foreign ministry said.
His son, Francisco Perez de Cuellar, said his father died at home of natural causes.
The former diplomat began his tenure as UN secretary-general on January 1, 1982.
He was “an outstanding Peruvian, a full-bodied democrat, who dedicated his life and work to making our country great,” tweeted Peruvian President Martín Vizcarra late on Wednesday.
His funeral will be held at Peru’s foreign ministry on Friday.
Mr Perez de Cuellar sought to revitalise the UN's peacekeeping machinery, working diligently to bring reforms to the world body in the face of what he saw as its dwindling effectiveness.
With the 1982 Israeli invasion of Lebanon, and with conflicts raging in Afghanistan and Cambodia and between Iran and Iraq, he complained to the general assembly that UN resolutions "are increasingly defied or ignored by those that feel themselves strong enough to do so."
"The problem with the United Nations is that either it's not used or misused by member countries," he said in an interview at the end of his first year as UN Secretary General.
During his decade as UN chief, Mr Perez de Cuellar would earn a reputation as a diligent and quiet diplomat. "Le ton fait la chanson," he was fond of saying, meaning that melody is what makes the song and not the loudness of the singer.
Faced early in his first term with a threatened US cut-off of funds in the event of Israel's ouster, he worked behind the scenes to help the Jewish state retain its General Assembly seat, prompting was muted criticism from the Arab camp that he had given the Americans the right of way in the Middle East.
In July 1986, Mr Perez de Cuellar underwent a quadruple coronary bypass operation, putting in question his availability for a second term. From the outset, he had insisted that he would be a one-term secretary-general. But he did come back for a second term after a groundswell of support for his candidacy.
He spent much of his second term working behind the scenes on the Lebanon hostage issue, resulting in the release of Westerners that had been held for years by Islamic militants.
Mr Perez de Cuellar’s diplomacy helped bring an end to several conflicts, his list of successes includes putting an end to fighting in Cambodia and in the 1980-88 Iran-Iraq war, crafting a peace pact between the Salvadoran government and leftist rebels, and assisting in the withdrawal of Soviet troops from Afghanistan.
The trilingual diplomat was born in Lima on January 19, 1920. He received a law degree from Lima's Catholic University in 1943 and joined the Peruvian diplomatic service a year later. He would go on to postings in France, Britain, Bolivia and Brazil before returning to Lima in 1961, where he served in a number of high-level ministry posts.
After leaving the UN, Mr Perez de Cuellar made an unsuccessful bid for Peru's presidency in 1995.
At the age of 80, he emerged from retirement in Paris and returned to Peru to continue his political work. Between foreign assignments, he was professor of diplomatic law at the Academia Diplomatica del Peru and of international relations at the Peruvian Academy for Air Warfare.
He was married to the former Marcela Temple and had a son, Francisco, and a daughter, Cristina, by a previous marriage.