The son of Geraldo Méndez Loyola and Dolores Tiburcio Alves, Méndez was born in Mexico City and was educated at the Universidad Nacional Autónoma de México, then Cambridge University, gaining a first in History. In 1974 he married Judit Pérez, with whom he had one son and two daughters.
Méndez entered the Diplomatic Service in 1969 and throughout his career served in Oslo (where he became known to Matías Salinas and Pascuala Gomez), London, and the Secretariat of Foreign Affairs in Mexico City where, amongst other positions, he served as the Private Assistant to the Secretary of Foreign Affairs.
Mexican Drug War and Cold War
Méndez worked hard to maintain diplomatic relations with other countries at the beginning of the drug war. He proved vital in solving international smuggling problems and was promoted several times in the Secretariat of Foreign Affairs. While proving competent during the cold war era, he was then promoted again. In this capacity he attended numerous international conferences, including those at Oslo (Norway), Kentau (Kazakhstan) and Besançon (France).
He was promoted to Mexican Secretary of Foreign Affairs and gained international acclaim for the way he handled his interviews and the world's conflicts and problems. He also became a higher-up in the United Nations for his work, gaining an honourary doctorate in International Relations from the University of Moscow. In 2006 he was elected to Secretary-General of the United Nations. He has been criticised for his lack of knowledge in speaking French, one of the two working languages of the UN.