Isidore of Seville’s Chronica Maiora was written in two redactions in early seventh century and reveals a great deal about the political, religious and intellectual history of late antique and early medieval Spain. a comparative analysis of the different versions demonstrates the author in action, responding to a range of contemporary stimuli. On a series of levels, the changing form and contents of the chronicle can be mapped against a rapidly changing religious and political background to provide valuable historical data and insights into the working methods and intellectual world of the most important author of early medieval Spain. This article offers a brief introduction to the text and its context of production before presenting an English translation of the two redactions of the text.