This author was earlier called the Anonymus Neveleti, referring to attribution in the seventeenth-century Mythologia Aesopica of Isaac Nicholas Nevelet. The name Walter (Latin Gualterus) was produced by Léopold Hervieux, on the basis of manuscript evidence, and he went on to identify the author as Walter of the Mill, archbishop of Palermo from 1168 onwards. Scholars have disputed this second step of identification; it may no longer be supported. The entire attribution is attacked.
The collection and its influence 
This collection of 62 fables is more accurately called the verse Romulus, or elegiac Romulus (from its elegiac couplets). Given the uncertainty over the authorship, these terms are used in scholarly works.
There is an earlier prose version of Romulus, also; it has been dated as early as the tenth century, or the sixth century. It is adapted from Phaedrus; the initial fable "The Cock and the Jewel", supposedly the reply of Phaedrus to his critics, marks out fable collections originating from this source. Walter changed the "jewel" from a pearl to jasper.
When John Lydgate produced Isopes Fabules, the first fable collection written in English, the verse Romulus was a major source. Particularly sophisticated use of this fable tradition is made later in the 15th century in Robert Henryson's Morall Fabillis, written in Scots.
Early printed editions appeared under the title Aesopus moralisatus, around 1500.
- Julia Bastin (editor) (1929–30), Recueil général des Isopets (two volumes)
- Sandro Boldrini (1994), Uomini e bestie: le favole dell Aesopus latinus
- Aaron E. Wright (editor) (1997), The Fables of "Walter of England", Edited from Wolfenbüttel, Herzog August Bibliothek, Codex Guelferbytanus 185 Helmstadiensis
- Paola Busdraghi (editor)(2005), L'Esopus. attribuito a Gualtiero Anglico
- Galterus, Gualtherus Anglicus, Waltarius; Walter the Englishman, Walter of England, Walther; Gauthier or Gautier l'Anglais; Anonyme de Nevelet.
- In Les fabulistes latins depuis le siècle d'Auguste jusqu'à la fin du Moyen-Age, 1893-4.
- L. J. A. Loewenthal, For the Biography of Walter Ophamil, Archhishop of Palermo, The English Historical Review, Vol. 87, No. 342 (Jan., 1972), pp. 75-82.
- Bruno W. Häuptli (2005). "Walter von Palermo (Gualtiero di Palermo, Gautier de Palerme, Gualterius Palermitanus; angeblich auch: Waltherus Anglicus, Gualtiero Anglico, Gualterus Ophamilius, Walter of Mill, Gualtiero Offamilio)". In Bautz, Traugott. Biographisch-Bibliographisches Kirchenlexikon (BBKL) (in German) 25. Nordhausen: Bautz. cols. 1447–1453. ISBN 3-88309-332-7.
- Cataldo Roccaro, Sull'autore dell'Aesopus comunemente attribuito a Gualtiero Anglico, Pan: studi dell'Istituto di Filologia Latina, Università degli Studi, Palermo 17 (1999).
- http://bcs.fltr.ucl.ac.be/FE/06/fable.html#transmission, in French.
- Medieval Latin Online (University of Oklahoma)
- A. G. Rigg, History of Anglo-Latin Literature, 1066-1422 (1992) states that 58 of the 62 tales were from Phaedrus, via the prose Latin of 'Romulus'.
- John MacQueen, Complete and Full with Numbers: The Narrative Poetry of Robert Henryson (2006), p. 15.
- , Wikisource text
- R. Howard Bloch, The Anonymous Marie de France (2006), p. 122.
- Ronald L. Durling, The Divine Comedy of Dante Alighieri: Inferno (1997), notes to Canto 23.4-6, p. 354.
- http://gahom.ehess.fr/thema/recueil.php?id=2&lg=fr, in French.
- Edward Wheatley, Mastering Aesop: Medieval Education, Chaucer, and His Followers, p. 125.
- Annabel M. Patterson, Fables of Power: Aesopian Writing and Political History (1991), p. 31.
- The Morall Fabillis, Notes
- http://www.luc.edu/publications/medieval/vol17/17ch6n.html note 14.
- The Morall Fabillis: Introduction