Egeria, Etheroiua or Aetheria was a woman, widely regarded to be the author of a detailed account of a pilgrimage to the Holy Land. The long letter, dubbed Peregrinatio (pilgrimage) or Itinerarium Egeriae, is addressed to a circle of women at home. Historical details it contains set the journey in the early 380s, making out the earliest of the kind. It survives in fragmentary form in a later copy - lacking a title, date and attribution.
The middle part of Egeria's writing survived and was copied in the Codex Aretinus, which was written at Monte Cassino in the 11th century, while the beginning and end are lost. This Codex Aretinus was discovered in 1884 by the Italian scholar Gian Francesco Gamurrini, in a monastic library in Arezzo. Recently, Prof. Jesús Alturo has identified two new fragments from one manuscript circa 900 in Caroline script.
Gamurrini published the Latin text and theorised the author was Saint Sylvia of Aquitaine. Others suggested Galla Placidia. In 1903 Marius Férotin claimed the author is one Aetheria or Egeria, known from a letter written by the 7th century Galician monk Valerio of Bierzo, and the date of travel was taken, about 381–384. Following editions accepted this attribution.
It is through Valerio's letter that we first see the name Aetheria, and have much of the biographical information. He praises Egeria and identifies her as a nun, perhaps because she addresses her account to her "sorores" (Latin for "sisters") at home. However, others (including Hagith Sivan, 1988) have pointed out that during Egeria's time it was common to address fellow lay Christians as "sisters" and "brothers." It is possible that Egeria used the term to address her Christian acquaintances. Valerio may also have believed her to be a nun because she went on such a pilgrimage, although lay women of the time are known to have engaged in such religious tourism. Egeria’s ability to make a long and expensive journey by herself, her numerous acquaintances and attentive guides in the places she visited, and her education indicate her middle or upper class wealthy background. Both the itinerary and Valerio mention the "ocean" (the latter perhaps quoting), which suggests he was writing about a person travelling from the Roman Gallaecia. Others maintain the pilgrim was from Gaul.