Question: The Prince-Archbishopric of Salzburg was founded in 739 by which leading figure in the Anglo-Saxon mission to the Germanic parts of the Frankish Empire during the 8th century?

full_context: Document 1: Saint Boniface: Saint Boniface (Latin: "Bonifatius" ; 675 – 5 June 754 AD), born Winfrid, Wynfrith, or Wynfryth in the kingdom of Wessex in Anglo-Saxon England, was a leading figure in the Anglo-Saxon mission to the Germanic parts of the Frankish Empire during the 8th century. He established the first organized Christianity in many parts of Germania. He is the patron saint of Germania, the first archbishop of Mainz and the "Apostle of the Germans". He was killed in Frisia in 754, along with 52 others. His remains were returned to Fulda, where they rest in a sarcophagus which became a site of pilgrimage. Facts about Boniface's life and death as well as his work became widely known, since there is a wealth of material available—a number of "vitae", especially the near-contemporary "Vita Bonifatii auctore Willibaldi", and legal documents, possibly some sermons, and above all his correspondence.
Document 2: Boniface Association: The Boniface Association, in German Bonifatiuswerk, is a Roman Catholic organization whose primary aim is to support Catholicism in largely Protestant areas of Germany and areas formerly part of the German empire. Founded in 1849 and still in existence, it owes its name to Saint Boniface, traditionally hailed as "The Apostle of the Germans."
Document 3: Duchy of Carniola: The Duchy of Carniola (Slovene: "Vojvodina Kranjska" , German: "Herzogtum Krain" ) was a State of the Holy Roman Empire, established under Habsburg rule on the territory of the former East Frankish March of Carniola in 1364. A hereditary land of the Habsburg Monarchy, it became a constituent land of the Austrian Empire in 1804 and part of the Kingdom of Illyria until 1849. A separate crown land from 1849, it was incorporated into the Cisleithanian territories of Austria-Hungary from 1867 until the state's dissolution in 1918. Its capital was Ljubljana.
Document 4: Donar's Oak: Jove's Oak ("interpretatio romana" for Donar's Oak and therefore sometimes referred to as Thor's Oak) was a sacred tree of the Germanic pagans located in an unclear location around what is now the region of Hesse, Germany. According to the 8th century "Vita Bonifatii auctore Willibaldi", the Anglo-Saxon missionary Saint Boniface and his retinue cut down the tree earlier the same century. Wood from the oak was then reportedly used to build a church at the site dedicated to Saint Peter. Sacred trees and sacred groves were widely venerated by the Germanic peoples.
Document 5: Theodor Schieffer: Theodor Schieffer (11 June 1910 in Bad Godesberg – 9 April 1992 in Bad Godesberg) was a German historian. He was professor of medieval history at the University of Mainz, then at the University of Cologne, and since 1952 he was president of the Association for Middle Rhine Church History. He is the author of "Winfrid-Bonifatius und die christliche Grundlegung Europas", the authoritative biography of Saint Boniface.
Document 6: Willibrord: Willibrord (Latin: "Villibrordus" ; 658 – 7 November AD 739) was a Northumbrian missionary saint, known as the "Apostle to the Frisians" in the modern Netherlands. He became the first Bishop of Utrecht and died at Echternach, Luxembourg.
Document 7: Magnus of Füssen: Saint Magnus of Füssen, otherwise Magnoald or Mang, was a missionary saint in southern Germany, also known as the Apostle of the Allgäu. He is believed to have been a contemporary either of Saint Gall (died 627) or of Saint Boniface (died 754) and is venerated as the founder of St. Mang's Abbey, Füssen.
Document 8: County of Tyrol: The Princely County of Tyrol, until 1493: County of Tyrol, was a State of the Holy Roman Empire established about 1140. Originally a jurisdiction under the sovereignty of the Counts of Tyrol, it was inherited by the Counts of Gorizia in 1253 and finally fell to the Austrian House of Habsburg in 1363. In 1804 the Princely County of Tyrol, unified with the secularised Prince-Bishoprics of Trent and Brixen, became a crown land of the Austrian Empire in 1804 and from 1867 a Cisleithanian crown land of Austria-Hungary.
Document 9: Salzburg: Salzburg (] ; Bavarian: "Såizburg" ; literally: "Salt Fortress") is the fourth-largest city in Austria and the capital of the federal state of Salzburg.
Document 10: Archbishopric of Salzburg: The Prince-Archbishopric of Salzburg (German: "Fürsterzbistum Salzburg" ) was an ecclesiastical principality and state of the Holy Roman Empire. It comprised the secular territory ruled by the Archbishops of Salzburg, as distinguished from the much larger Catholic diocese founded in 739 by Saint Boniface in the German stem duchy of Bavaria. The capital of the archbishopric was Salzburg, the former Roman city of "Iuvavum ".
Document 11: Schönborn family: Schönborn is a noble and mediatised former sovereign princely family from the former Holy Roman Empire. Several members of the family have held high offices of the Roman Catholic Church and the Holy Roman Empire over the course of centuries, including as Bishops, Prince-Bishops, Cardinals and Prince-Electors. In addition to several family members having been elected monarchs of ecclesiastical principalities—the Electorate of Mainz, the Prince-Bishopric of Würzburg, the Prince-Bishopric of Worms, the Prince-Bishopric of Speyer, the Electorate of Trier, and the Prince-Bishopric of Bamberg—the family possessed a fiefdom in Franconia that held imperial immediacy, and was thus a principality of the Holy Roman Empire, the state of Schönborn.
Document 12: Apostolic Nuncio to Bavaria: The Apostolic Nunciature to Bavaria was an ecclesiastical office of the Roman Catholic Church in Bavaria. It was a diplomatic post of the Holy See, whose representative was called the Apostolic Nuncio to Bavaria, a state – consecutively during the nunciature's existence – of the Holy Roman Empire, of its own sovereignty, and then of Imperial, Weimar and finally Nazi Germany. The office of the nunciature was located in Munich from 1785 to 1936. Prior to this, there was one nunciature in the Holy Roman Empire, which was the nunciature in Cologne, accredited to the Achbishop-Electorates of Cologne, Mainz and Trier.
Document 13: Sacerdotal state: A sacerdotal state is a state whose head of state is also an ecclesiastical leader designated by a religious body. An example of this kind of state is the Vatican City, whose head of state is the Pope of the Catholic Church. Andorra operates under a semi-sacerdotal system, as one of its co-heads of state is the Bishop of Urgell. In the past it was common for bishops to assume civil as well as clerical power and rule as Prince-Bishops.
Document 14: Anglo-Saxon mission: Anglo-Saxon missionaries were instrumental in the spread of Christianity in the Frankish Empire during the 8th century, continuing the work of Hiberno-Scottish missionaries which had been spreading Celtic Christianity across the Frankish Empire as well as in Scotland and Anglo-Saxon England itself during the 6th century (see Anglo-Saxon Christianity).
Document 15: Holy Roman Empire: The Holy Roman Empire (Latin: "Sacrum Imperium Romanum" ; German: "Heiliges Römisches Reich" ) was a multi-ethnic complex of territories in central Europe that developed during the Early Middle Ages and continued until its dissolution in 1806. The largest territory of the empire after 962 was the Kingdom of Germany, though it also came to include the Kingdom of Bohemia, the Kingdom of Burgundy, the Kingdom of Italy, and numerous other territories.
ground_truth: Saint Boniface