The greatest patrons of illuminated books in the period were the monastic houses; but the artists themselves were not necessarily monks. In the near-absence of technical manuals and model-books, the manuscripts themselves – especially when unfinished – provide the only evidence for artistic techniques. The chapter interrogates the term ‘Romanesque’ and attempts to characterize and to understand the relation between the text and its decoration, especially in the form of initial letters, whether decorated (usually with foliate shapes) or historiated (containing narrative illustration). It ends by mapping the illustrative traditions applied to different texts in the period, from Christian biblical, liturgical, and theological texts to literary, medical, and scientific works, which had often travelled far from their origins in the classical world.