Imagine being a medieval monk assigned to manuscript illumination duty. Sure, it's probably the most fun job in the monastery—but work's work, and after a certain point flowers and Bible scenes can get a little boring. So your thoughts turn to adventure: a courageous knight in shining armor, ready for battle... against a giant snail?

Strange as it may sound, scenes of knights battling the garden pests appear in countless Gothic-style manuscripts, and are a particularly common sight in those dating from the 14th century.

In his book Images on the Edge: The Margins of Medieval Art, art historian Michael Camille briefly touched on the phenomenon. According to Camille, the first modern person to hypothesize about the trope was Auguste de Bastard d'Estang, a 19th-century French count and writer. According to his theory, the snails had a religious connotation: "the creature emerging from its shell was a symbol of the Resurrection." 

There have been many interpretations of the ubiquitous knight and snail motif since. According to one Flemish historian of caricature, the snail in its safe shell was a ‘satire on the powerful who in their fortified castles laughed at the threat of the poor whom they exploited.’ But this does not explain why snails were the object of chivalric attention.

Another art historian named Lillian Randall interpreted the bizarre battle scenes as political statements, arguing that the snails served as stand-ins for the unpopular Lombards. In 2014, blogger and Yale University graduate student Carl Pyrdum dug up a simpler explanation also first proposed by Randall: “We’re supposed to laugh at the idea of a knight being afraid of attacking such a “heavily armored” opponent. Silly knight, it’s just a snail!" But so far no interpretation has ever fully satisfied medieval historians and art historians, even as the mystery grows more and more notorious.

All images via the British Library