This six-volume work, published in Vienna between 1860 and 1890, contains a selection of documents in Greek which throw light on the history and politics of the Byzantine Empire in the Middle Ages. The editors, Franz Miklosich (1813-91), philosopher, linguist and Slovenian nationalist, and Josef (or Giuseppe) Muller (1823-95), a Greek scholar who also translated many important works by German classical historians into Italian, used as one of their sources the volumes of Greek manuscripts brought back to Vienna by Ogier Ghiselin de Busbecq (1522-92), the Flemish diplomat, herbalist, and travel writer who had acted as Imperial Ambassador to the Sublime Porte. Volume 2 (published in 1862) contains further letters and decrees of the fourteenth-century Patriarchs of Constantinople, acting to settle conflicts in the Russian churches of Kiev and Novgorod, and trying to reconcile the warring co-emperors (father and son) John V and Andronicus IV Palaeologus.