Renaud de Montauban, (also spelled Renaut, Renault, Italian: Rinaldo di Montalbano, Dutch: Reinout van Montalba(e)n) was a fictional hero and knight who was introduced to literature in a 12th-century Old French chanson de geste known as Les Quatre Fils Aymon ("The Four Sons of Aymon") (frequently referred to simply as [the tale of] Renaud de Montauban). The four sons of Duke Aymon are Renaud, Richard, Alard, and Guiscard, and their cousin is the magician Maugris (French: Maugis, Italian: Malagi, Malagigi). Renaud possess a magical horse Bayard and the sword Froberge (Italian: Fusberta, Frusberta).
The story of Renaud had a European success. The tale was adapted into Dutch, German, Italian and English versions throughout the Middle Ages, inspired the Old Icelandic Mágus saga jarls, and also incited subsequent sequels and related texts that form part of the Doon de Mayence cycle of chansons. Renaud, as Rinaldo, is an important character in Italian Renaissance epics, including Morgante by Luigi Pulci, Orlando Innamorato by Matteo Maria Boiardo and Orlando Furioso by Ludovico Ariosto.
The oldest extant version of the anonymous Old French chanson de geste Quatre Fils Aymon dates from the late 12th century and comprises 18,489 alexandrine (12 syllable) verses grouped in assonanced and rhymed laisses (the first 12,120 verses use assonance; critics suggest that the rhymed laisses derive from a different poet). It is one of the longest of all the chansons de geste. Other versions range from 14,300 to 28,000 verses. It was transformed into prose romances in the 14th and 15th centuries, and, judging from the number of editions, the prose Quatre Fils Aymon was the most popular romance of chivalry in the late 15th and first half of the 16th century in France. The tale was the basis of other medieval versions in Italian, German, Dutch and English.