In the middle of the 7th century an anonymous cleric from Ravenna, Italy wrote a description of the world in five books. Though entirely the result of compilation, according to J.K. Wright this cosmography is in many respects the most elaborate and interesting geographical book dating from the early medieval West. The sources quoted and utilized are extremely varied, including the Bible, "Jordanis" [Jordandes], Orosius, Isidore, pagan authors such as Porphyry, Iamblichus, Aristarchus and Lollianus, Ptolemy (whom he styles erroneously 'King of the Macedonians in Egypt'), and possibly the Tabula Peutingeriana (Slide #120), in addition to a number of Greek, Roman and Gothic writings otherwise unknown. The unknown author most frequently cited is a Roman cosmographer of the name of Castorius. The citations, names and extracts from Castorius correspond very closely to the legends on the Tabula Peutingeriana and have led scholars such as Konrad Miller to the conclusion that the latter represents the work of Castorius (presumably a Roman cosmographer of the 3rd century).

Many scholars have presumed that a map of the world accompanied this Ravenna treatise, even though none has survived. Yet the map of the Ravennese, if it was ever really executed, must have been very different from such itinerary-type plans as the Tabula Peutingeriana, considering the anonymous geographer's written descriptions. Was it round, square, oval, or of some other shape ? Was it planned from a center at Jerusalem, Constantinople, or Ravenna itself ? Or was it, after all, only the work of the Castorius whom the Ravennese so constantly quotes, and who was possibly the the compiler of a pictorial itinerary of the classical pattern ? Included here are two attempts at a reconstruction of the "map of the anonymous geographer from Ravenna", the first from the facsimile atlas of Professor Miller, the second from Beazley with a Ravenna-centered oval reconstruction modified from that by Avezac. Kiepert has given, in Pinder and Parthey's edition of the Ravennese, a circular restoration, with Jerusalem in the center; Marinelli (Erdkunde, 71-74) has argued very skillfully for a middle point at Constantinople; while Lelewel believes that the map of the Ravennese was right-angled.

The main importance of the work of the anonymous geographer from Ravenna in relation to the geography of the Crusading age lies in the fact that a large portion of it was included in a compilation made by a Guido in 1119 (Slide #216).