Manuscript 751 of the National Austrian Library at Vienna is a composite volume consisting of four unrelated parts. The first part (ff. 1-77) is dated from the mid-ninth century and contains a large section of the correspondence of St Boniface and St Lullus (35 letters of Boniface and 12 addressed to him; 16 letters of Lullus and 24 addressed to him) together with other letters by several of their contemporaries. The Vienna Codex is one of the three oldest codices containing the Boniface correspondence; this section was most likely copied in Mainz – Boniface had been appointed archbishop of Mainz in 745, and the copyist used originals of the letters available there. The codex was later moved to Cologne, where it was marked (on 166v) as belonging to the library of the Cologne Cathedral. The modern history of the codex begins in 1554 when Kasper von Niedbruck, who had entered the service of Maximilian II in that year, found the manuscript in Cologne and brought it to Vienna. Von Niedbruck collected materials to aid with the composition of the Magdeburg Centuries (a comprehensive church history first published in 1559), and gathered many manuscripts for the Imperial Library, which he allowed Matthias Flacius and his collaborators to copy. As indicated in von Niedbruck's correspondence, the codex was sent to George Cassander after September 1755. Next mention of the codex is in the catalog entry by Hugo Blotius, the first librarian of the Imperial Library, in 1597. Correspondence between Sebastian Tengnagel of the Imperial Library and Johann Pistorius, confessor to Rudolf II, indicates that the codex was in Prague, whence Tengnagel had sent it to Nicolaus Serarius in Mainz who used it to publish his edition of the Boniface correspondence (1605). Corrections and notes in the hands of Tengnagel and Blotius prove that they had already worked on copying and editing the correspondence before the codex was sent to Prague. It is not known when the codex returned to Vienna, though it was there by 1802, when the German historian Georg Heinrich Pertz read it. It was used also by Philipp Jaffé (who published an edition of the correspondence in 1866), and, according to the visitors log in Vienna, between 27 October and 20 November 1882 it was studied almost daily by Wilhelm Diekamp. The codex later traveled to Berlin, where Michael Tangl used it for his own edition (published 1916), and to Essen, where it was exhibited in 1956. The handwriting of the Boniface collection is a careful Carolingian minuscule from the mid-ninth century. The manuscript is written by a single scribe, with the exception of the two last pages, which are written in a different though contemporary hand.
We have 1 facsimile edition of the manuscript "Sancti Bonifacii Epistolae": Sancti Bonifacii epistolae facsimile edition, published by Akademische Druck- u. Verlagsanstalt (ADEVA), 1971