Roman Catholic Cardinal. A native of Banja Luka in the then Austro-Hungarian Empire, present day Bosnia and Herzogovina, Guido Del Mestri was the youngest of the six children of Count Gian Vito Del Mestri and his wife Baroness Marianna Degrazia. Holding the title of count, he received his initial studies in Banja Luka, later studying classics at the Jesuit Lyceum of Kalksburg, Vienna, before entering the Almo Collegio Capranica of Rome. In the meantime, he also underwent studies at the Pontifical Gregorian University, obtaining doctorates in philosophy, theology and canon law. Ordained priest on April 11, 1936, at the Patriarchal Lateran Basilica of Rome by Cardinal Francesco Marchetti Selvaggiani, he was incardinated in the diocese of Gorizia, where he briefly performed pastoral ministry and served as faculty member of the minor Seminary until 1938 when he moved once again to Rome, pursuing studies in diplomacy at the Pontifical Academy of Ecclesiastical Nobles. Attaché of the nunciature in Yugoslavia from 1940 till 1941, he was successively named secretary of the apostolic delegation in Lebanon, where he stayed until 1943. Appointed Privy Chamberlain of His Holiness with the title of monsignor on October 21, 1941, he was assigned as secretary, and later auditor, of the apostolic nunciature in Romania, an office which he held until July 1950, when he was expelled from the named country by the Communist regime. Attached to the Secretariat of State of the Vatican City, he was named Domestic Prelate of His Holiness on October 6, 1951. Charged with the opening the apostolic nunciature in Syria as chargé d'affaires in 1951, he stayed there until 1953 when he was assigned in the same post to the apostolic nunciature in Indonesia. Counselor for the nunciature in Germany between 1953 and 1959, Monsignor Del Mestri was named apostolic delegate in British Eastern and Western Africa with residence in Nairobi on October 3, 1959. After the delegation was divided into Central-Western, Western and Eastern on September 23, 1960, he continued serving as apostolic delegate in Eastern Africa with residence in Lagos. Pope John XXIII elected him archbishop of the titular see of Tuscamia on October 28, 1961, receiving his episcopal consecration on the following December 31 inside the cathedral of the Holy Family in Nairobi from Cardinal Laurean Rugambwa. Named pro-nuncio for Kenya in November 1965, he was appointed apostolic delegate in México on September 9, 1967 and later pro-nuncio in Canada on June 20, 1970. Successively, he served as apostolic nuncio in Germany from August 12, 1975, until his resignation at 73 years of age on August 3, 1984. At eighty years of age, Archbishop Del Mestri was elevated to the Sacred College of Cardinals by Pope John Paul II in the consistory of June 28, 1991, as cardinal deacon of the deaconry of Sant'Eustachio. In his retirement, he went on serving as chaplain of the Theresienklinik hospital of Nürnberg, Germany, where he eventually passed away on August 2, 1993. His remains are found interred inside the family chapel of St. Anthony, near Medea, Gorizia, Italy.