Modestus was an 8th-century Irish monk and priest who served as a missionary to the Carantanians, an Alpine Slavic people. A disciple of Virgil of Salzburg, he was sent to the region around 755 to evangelize the population at the request of Prince Cheitmar. Known as the Apostle of Carinthia, he played a significant role in establishing Christianity among the Slavic ancestors of modern Slovenes and Austrians, helping to stabilize the territory during a period of political transition.
Missionary work
Acting as a chorbishop, Modestus led a group of clergy to convert the local Slavic population. He is credited with constructing three churches, including sites near Teurnia and Maria Saal. His efforts were documented in historical texts to highlight the successes of the Salzburg Archdiocese in converting the Slavs. He is also noted for baptizing the Carinthian prince Domitian of Huy.
Veneration
Because of his successful conversion efforts, he is remembered as the Apostle of Carinthia. He is venerated as a saint in both the Roman Catholic and Eastern Orthodox traditions. His feast day is observed on 5 February, and his purported tomb is located within the Gothic church at Maria Saal.