The Etymologicum Magnum (Ancient Greek: Μέγα Ετυμολογικόν) or Etymologicum genuinum was a grammatical encyclopedia edited at Constantinople in the 9th century AD. The Ancient Greek language is the historical stage in the development of the Hellenic language family spanning the Archaic (c Constantinople (Κωνσταντινούπολις Konstantinoúpolis, or gr ἡ Πόλις hē Polis, Latin: la CONSTANTINOPOLIS The work, which is alphabetical to the third letter, borrows from Choiroboskos, Herodian, Methodius, Orion, Oros and Theognostos. Aelius Herodianus (Latin Greek) or Herodian, ca 180-250 was one of the most celebrated grammarians of Greco-Roman antiquity Methodius may refer to Methodius of Olympus (d 311 Christian bishop church father and martyr Methodius I of Constantinople (c Orion of Thebes (died ca 460s was a 5th century Grammarian of Thebes (Egypt, the teacher of Proclus the neo-Platonist and of Eudocia the wife of Emperor Photius, patriarch of Constantinople, took up the Etymologicum, which had been started by an unknown grammarian. Grammar is the field of Linguistics that covers the Rules governing the use of any given natural language. In this and the recension called Etymologicum parvum that followed it Photius became the founder of the Greek etymological lexical works that were compiled in the 12th and 13th centuries, such as the etymologies known under the titles Etymologicon magnum and Etymologicum Symeonis; their manuscript sources are sometimes more complete. Etymologicon Magnum ( Ετυμολογικόν Μέγα) is a Lexicon of the Greek language written by an unknown Lexicographer around 1100 AD Its modern name was given it by its editor in the nineteenth century, Richard Reitzenstein. Richard August Reitzenstein (1861-1931 was a German classical philologist and scholar of Ancient Greek religion, Hermetism and Gnosticism. No existing manuscript of the work is complete. Most of the Etymologicum Genuinum remains unpublished, and some of the only published material is of the 19th century. These etymologies are useful for the quotations they preserve of literary works otherwise lost.