Rabanus Maurus was a Benedictine monk, archbishop of Mainz, writer and poet who lived between c.780 and 856. A very sophisticated intellectual, he was considered one of the most important teachers and encyclopedists of the Carolingian age.
Among his body of work, (treatises, commentaries of the Bible, military texts, etc.), he wrote De laudibus sanctae crucis (“The praise of holy cross”), a collection of manuscript poems centred on the cross, presenting the sacred symbol in words, images, and numbers.
The work included a number of miniature paintings based on the abstraction of the cross through graphic elements, over backgrounds formed by grids of letters, each line corresponding to a poem. Only on a number of pages, the figures of Christ, of angels and of the writer himself among other recognizable figures appear.
The isolated letters corresponding to the graphic elements of the cross on each miniature reveal new poems subtly overlapping the main rows. The same happens with the letters superposed to the human or holy figures in some pages.
For an interesting exegesis of the signification of the poems and the relationship of Rabanus with the cult of the icons, you can read Philippe Cibois’ “Raban Maur, la querelle des images et l’art contemporain,” an article which also cites the exhibition founded in 2018 by the BNF in France, in which contemporary artist Jan Dibbets was given carte blanche to associate the miniatures to works of contemporary art.
You can find a digital copy of De laudibus sanctae crucis on Gallica.