This work, first published in 1822, was edited by Peter Paul Dobree (1782-1825) who had been entrusted with the literary remains of the eminent classical scholar Richard Porson (1759-1808). It contains the text of a ninth-century Greek lexicon compiled by Photius, Patriarch of Constantinople. The lexicon was a tool for Byzantine Greeks studying the works of ancient authors, whose language and vocabulary differed significantly from the day-to-day language spoken in the Byzantine Empire. The lexicon offers the modern scholar a wealth of information regarding ancient works that Photius had access to but are no longer extant. The edition is based on a transcription, made by Porson, of the only remaining manuscript of the lexicon: Codex Galeanus, in Trinity College Library, Cambridge. Volume 2 contains entries for the letters pi to omega. The edition has served as an important source for the study of Byzantine lexicography.
