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.