Modestus (720 – before 772),[1] called the Apostle of Carinthia or Apostle of Carantania, was most probably an Irish monk and the evangeliser of the Carantanians, an Alpine Slavic people settling in the south of present-day Austria and north-eastern Slovenia, who were among the ancestors of present-day Slovenes.
Modestus was an Irishman by birth, a disciple of St. Fergil. He may have come to the Bavarian lands under Duke Odilo in the wake of Fergil (Vergilius), who, about 767 was consecrated Bishop of Salzburg.
Upon the request of Prince Cheitmar or Hotimir[2] of Carantania to Christianize his people, Bishop Vergilius dispatched Modestus around the year 755, together with four priests and a deacon "and other inferior clerks"[3] as a missionary with the rank of a chorepískopos (Greek, Ancient (to 1453);: Χωρεπίσκοπος), i.e. a chorbishop responsible for the people in the countryside.[4] Modestus received authority as a bishop, but probably, after the Irish custom, was without a definite see. It is only in the late anonymous life of Gebhard of Constance, that he is called bishop of Liburnia.
Cheitmar's predecessor Borut had accepted Bavarian overlordship about 740 and Modestus' missionary work in Carantania was meant to stabilise the country against the invading Avars. It was described in the Conversio Bagoariorum et Carantanorum[5] written around 870 as a memorandum of the Salzburg archbishop Adalwin in a court hearing before the East Frankish king Louis the German against Bishop Methodius, the apostle of the Slavs in the Frankish Principality of Lower Pannonia and in Great Moravia. In the document, the Archdiocese of Salzburg emphasised the achievements of Modestus as an argument of their merits in converting the Slavs.
According to the chronicles, he built three Christian churches:
His church was thus in the immediate vicinity of the area that has served as a political and cultural centre of the region through the ages, close to:
Modestus is said to have baptised St. Domitian, a Carinthian prince, at Milstadt, which may, perhaps, be identical with Adandrinas.
According to the older manuscripts, Modestus stayed in Carinthia till his death; one late manuscript says he died in France. The most likely year of his death was 763, although other dates also appear in sources. No traces of his church of St. Mary have been discovered.
Dempster calls him a companion of Saint Boniface, and Ferrarius says he is mentioned in Boniface's life. It is probable that in both cases St. Fergil was meant. A manuscript by him, 'ad ecclesiam suam,' was said to be at Salzburg, and a volume of his letters at Strasburg. Neither manuscript can now be traced.
His alleged tomb is shown in the present Gothic church of Maria Saal, which was built six centuries later, replacing an earlier Romanesque church probably from the 12th century.
Due to his success in converting the pagan Carantanian Slavs to Christianity, Modestus was honoured by the popular denomination "Apostle of Carinthia". His feast is celebrated on 5 December.