In this article, 1 I seek to shed new light on a question which, to date, has been little more than a subtle chronological debate amongst historians. Previous studies have left little room for doubt that Robert of Torigni consulted Henry of Huntingdon's Historia Anglorum (referred to hereafter as HA) for the composition of his own magnum opus, the Chronica. 2 There is, however, much less certainty as to when, precisely, Robert first received a manuscript copy of Henry's work at the monastery of Le Bec in Normandy. Was it in 1139, the year in which Henry temporarily ceased his work in order to accompany Archbishop Theobald of Canterbury on a mission to the European mainland? Or was it several years later, when Henry had long since resumed his work on the HA, causing it to evolve into an even more substantial historical narrative? And why does it matter? Finding an answer to these questionshowever esoteric they might at first appearpromises to produce knowledge of which the significance extends beyond the intertextual relationship between Henry's HA and Robert's Chronica.By identifying the precise dynamics of Robert's interaction with Henry, as well as the logistics and channels of communication which connected the two historians and their works, I aim to offer an innovative lens through which to investigate similar texts and contexts in a wider chronological and geographical framework. 'Intertextuality', in this context, will be showcased not merely as a theoretical, but rather as a practical concept for the study of medieval historiography.I commence this study by challenging the prevailing notion that Robert was presented with a copy of the HA as early as 1139. Instead, I produce evidence to suggest a later date, one closer to Robert's appointment as prior of Le Bec in 1149. 3 My argument consists of three strands, represented here as three thematic sections. Each of these sections focuses on a separate yet related piece of the one argued for in this article. First, I analyse and compare different narrative accounts which testify to Robert's involvement with the HA. I then turn directly to the medieval manuscript tradition in order to develop a clearer notion as to which version or redaction of the text Robert is likely to have used for the composition of his Chronica. 4 Finally, I reassess the place of the HA within the monastic library of Le Bec during the twelfth century. Prior to commencing this line of enquiry, however, I must briefly recapitulate the argument for dating as it stands today.Generally speaking, scholarly consensus has it that Robert was first presented with a manuscript copy of the HA in 1139, the very year when Henry travelled to Le Bec in the company of Archbishop Theobald and, allegedly, showed Robert a manuscript containing his work-in-progress. 5 Scholars hypothesise that Henry granted Robert access to his working copy of the HA as an act of reciprocity, in return for being presented with a copy of Geoffrey of Monmouth's Historia regum Britanniae (referred to hereafter as HRB). Fol...