In the legendary material, as elaborated and expanded in various medieval texts, Aymeri is a knight in the time of Charlemagne's wars with the Saracens after the Battle of Roncevaux Pass.
The poem comprises 4,708 verses grouped into 122 rhymed laisses;[2] the verses are all decasyllables except for a short six syllable line at the end of each laisse (a similar use of shorter lines appears in the chansons de geste Aliscans and the Chanson de Guillaume).
Once he becomes lord of the city, Aymeri seeks the hand of Hermengarde, daughter of Didier, sister of Boniface the king of the Lombards in Pavia.
After various adventures, including difficulties with a German lord named Savari (to whom Hermengarde had been promised previously) and attacks from the Saracens, the marriage occurs.
[2] The Venice 4 manuscript of The Song of Roland contains, toward the end of that poem, the taking of Narbonne and Aymeri receiving it at his father's behest (laisses 285-318, https://www.rialfri.eu/rialfriWP/opere/chanson-de-roland-v-4).
The hero also appears in the chanson de geste entitled Narbonnais (c.1210) by an anonymous author from the Brie region.