Superficially, Jocelin's commission to write the Vita Helenae presented a similar project to the Vita Patricii. The central figures of each work were saints of international renown and both were already the subjects of a significant amount of literature. However, although an earlier hagiographical account of Helena seems to have been available for use as a primary base text, Jocelin chose to construct his work largely from other sources – the ‘diverse ecclesiastical histories and universal chronicles’ acknowledged by the prologue. In contrast to the composition of the Vita Patricii, Jocelin formed the Vita Helenae episode by episode, using the most detailed account he could find as a base text for each section and inserting, where possible, additional material from other sources. Yet this was no mere ‘cut-and-paste’ job. As seen previously, Jocelin shows a reluctance to paraphrase, let alone quote, long extracts from other works. Instead he condensed the information into his own prose, layering tradition upon tradition without distinction between the author or age of the source material. As in the previous chapter, these underlying texts are largely identified by content. However, the dense interweaving of source material found in the Vita Helenae means that many of these sources only become visible when anomalous information is provided or the Vita follows a unique narrative structure. Although such analysis has its limitations, it provides clear evidence of the extensive research conducted by Jocelin and the sheer amount of information that he was able to assemble and then reorder (a table listing Jocelin's apparent sources for this work can be found at the end of the chapter). To present as simply as possible what must have been an extremely complex process, this chapter is structured according to the broad chronology of the material, which is then assessed in order of Jocelin's dependence upon that source. However, considering the intricate layering of traditions found in the text, brief digressions concerning the material used to supplement the main sources are unavoidable.

The early sources

Although leaning heavily on Rufinus of Aquileia's expanded Latin translation of Eusebius's Ecclesiastical History and the Inventio crucis legend, Jocelin also had at hand a variety of other early sources that provided information on the life of Helena. The Liber pontificalis supplied details for Jocelin's references to church furnishings and there are also explicit references to Ambrose's De obitu Theodosii.