Liber Floridus 1121. The World in a Book takes us into the world of a medieval encyclopaedist. Through the eyes of Lambert of Saint-Omer we explore a strange reality, one which none the less shows certain similarities with our own observation. Our journey begins in Saint-Omer, one of the seven most important towns of the County of Flanders, where Lambert was a canon of the collegiate Church of St Mary. We are introduced to the intellectual world of his day, discover the importance of mappae mundi or world maps and the primacy of the image and, finally, learn how the Liber Floridus was created. The many illustrations in the Liber Floridus tell their own story, situating Lambert's imagery within the iconography of the eleventh and twelfth centuries.