# The Unique Liber Sermonum of Martin of León (c.1130–1203): The Third Crusade, Popular Preaching and the Liturgical Front

## TL;DR

This paper analyzes a 12th-century sermon collection by Martin of León, revealing his role in the Third Crusade and how liturgical texts reflect the broader crusade movement.

## Contribution

The study introduces a new method for identifying crusade-related themes in liturgical sermons, linking them to historical events and popular preaching.

## Key findings

- Martin of León's sermons show his involvement in multiple crusade-related conflicts, including anti-heretical and anti-Muslim actions.
- A Palm Sunday sermon provides direct evidence of Martin's engagement with the Third Crusade.
- Liturgical texts reveal how providential logic connected distant crusade arenas.

## Abstract

This article explores the exceptional Liber Sermonum composed by Martin of León around 1200. First, it describes the work in its manuscript form, illuminating the historical context of its production. Then, the article maps the occurrence of motifs pertinent to crusading throughout the Liber. This data unveils Martin’s expertise and, thus, involvement in several crusade arenas, straddling action against scholastics, Jews, heretics and ‘pagans’ (that is, Muslims). Lastly, three texts of the Liber are analysed in-depth: A Palm Sunday sermon evidences Martin’s involvement in depth the Third Crusade and anti-heretical action; a treatise on the Acts of the Apostles shows how he tried to promote popular preaching in León; and a treatise on rogation liturgy elucidates how a providential logic entangled various crusade arenas despite their geographical distance. The methodological tools developed for identifying ‘the crusade’ in these texts demonstrate the pertinence of liturgical sermons for studying the crusade movement.