John de Leoncello

John de Leoncello OSB (Latin: Johannes de Leoncello; Croatian: Ivan de Leoncello) was a prelate of the Catholic Church who served as the bishop of Duvno from 1345 to 1355.

Born in present-day France, John joined the Cistercian abbey in Léoncel near Rhone in present-day France which belongs to the Diocese of Valence as a young man.[1] In 1320, he was uncanonically consecrated a bishop by the excommunicated Archbishop of Bar Andrew, who appointed him the bishop of Chunavia in present-day Albania, although the diocese was subordinated to the Archdiocese of Durrës.[2][3] For this reason, John was suspended on 10 July 1325 by Pope John XXII who ordered him to return to his abbey in Léoncel without any episcopal honours. John submitted to the Pope's order and after spending several years in the Léoncel abbey he left the Cisterians and joined the Benedictine Abbey of Île Barbe, with the agreement from his superior and subsequent approval from the Pope.[2]

After Madius' resignation, Pope Clement VI lifted John's suspension and appointed him as his successor as the bishop of Duvno on 20 July 1345.[2] On 22 December 1345, he was exempted from paying a nomination fee due to poverty. Both of the documents were discovered by Dominik Mandić. As other documents are lacking, it is unclear whether John took over the diocese, or he was only a titular bishop. The document on his exemption from paying the fee speaks of the poor conditions of the Diocese of Duvno after its patrons from the Šubić family lost political influence.[3]