Partial funding: FWF projects P19818 (2007–2011), P22269 (2011–2015)

The chancery of the Patriarchate of Constantinople maintained a register with original documents and/or copies. The two extant volumes were transferred to Vienna (Austrian National Library, Cod. Vind. hist. gr. 47 and 48, of the 14th and early 15th century) from Constantinople in the middle of the 16th century by the imperial ambassador at the court of Suleyman II, Augerius Busbeck. These documents were published by Franz Miklosich and Joseph Müller in the first two volumes of the Acta et diplomata Graeca medii aevi (Vienna, 1869, 1862).

Since this publication does not satisfy the standards for a critical edition, Herbert Hunger initiated in the 1970s a new edition in co-operation between experts for Byzantine philology and canon law. This edition, planned for eight volumes, appears in the series Corpus Fontium Historiae Byzantinae (Series Vindobonensis). The first volume was published in 1981: a critical edition of the text with detailed introduction and analysis of each document, including references to earlier documents which are mentioned, and complemented by a synoptic German translation. The second volume was published in 1995, the third in 2001. Volumes 5 and 6 were supported by projects funded by the Austrian National Fund (P19818, P22269) and are under final revision. Volume 4 is being prepared for print in two parts.

The edition of the Register of Patriarchs was included in the long-term projects of the Austrian Academy of Sciences. In addition to the preparation of the editions, studies on social aspects, networks, language usage, historical sociolinguistics contribute to the analysis and interpretation of these documents. Two congresses were organized in recent years, the proceedings of which are published at the Austrian Academy of Sciences. Furthermore, the Viennese team edited a volume on the patriarchate of Constantinople in the series "Brill's Companion to the Byzantine World".