Girart de Roussillon

Girart de Roussillon, also called "Girard", "Gérard II", "Gyrart de Vienne," and "Girart de Fraite", (c. 810–877/879?) was a Burgundian chief who became Count of Paris in 837, and embraced the cause of Lothair I against Charles the Bald. He was a son of Leuthard I, Count of Fézensac and of Paris, and his wife Grimildis.
Girart is not described as being from Roussillon in authentic historical sources. The placename in his title is derived from a castle he built on Mont Lassois, near Vix and Châtillon-sur-Seine (Côte-d'Or).
Girart de Roussillon also is an epic figure in the cycle of Carolingian romances, collectively known as the "Matter of France." In the genealogy of the cycle's legendary heroes, Girart is a son of Doon de Mayence and appears in the various irreconcilable events.
Biography.
Girart fought at the Battle of Fontenay in 841, and doubtless followed Lothair I, his future brother-in-law, to Aix-en-Provence. In 843, he married Bertha, daughter of Lothair I (May 800 - Sep 855) and Ermengarde of Tours (800-851). Hugh II (780-837) was Bertha's grandfather.
In 855, Girart became governor of Provence for Lothair's son Charles, nominal king of Provence. His wife Bertha defended Vienne unsuccessfully against Charles the Bald in 870. Girart, who had perhaps aspired to be the titular ruler of the northern part of Provence, continued to administer it under Lothair II until that prince's death in 869. He retired with his wife to Avignon where he died probably in 877, certainly before 879.
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Girart de Roussillon married Bertha de Tours, b. 800 daughter of Hugues von Sundgau b. 775 and Ava de Morvois, b 769.
Lothair I's daughter Bertha (c. 830–852) Married to an unknown man, but later Abbess of Avenay.
source: 
Romance.
The legend of Girart's piety, the heroism of his wife Bertha, and of his wars with Charles passed into the genre of literary romance; however, the historical facts are so distorted that, in the epic "Girart de Roussillon", he became an opponent of Charles Martel who was married to Bertha's sister. The legendary narrative "Girart de Roussillon" was long held to be a Provençal work, but its Burgundian origin has been proven.
Accounts of Girart are found in several early manuscripts. The earliest "chanson de geste", called "Le Chanson de Girart de Roussillon", dates from the second half of the 12th century. The original text, written in rhymed decasyllables, is preserved at the Bibliothèque nationale de France (BnF). It was translated the first time by Paul Meyer in 1884, (Paris: Champion). A recent translation into modern French with notes by Micheline Combarieu du Grès and Gérard Gouiran was published in 1993 (Paris: Librairie générale française).
A romance written in rhymed alexandrines was written between 1330 and 1349 by monks in the abbey of Pothières, which was founded in about 860 by Girart. It was dedicated to Odo IV, Duke of Burgundy (ca. 1295–1350), and Jeanne de Bourgogne (called "Joan the Lame"), queen of France (1293–1349). The text is composed in a dialect midway between French and Old Occitan. Five manuscript copies of this version survive; two in Montpellier, France at the Bibliothèque Interuniversitaire (section médecine), one in Troyes (now held at the Bibliothèque de l'Arsenal in Paris), one in Paris at the BnF, and one in Brussels at the Bibliothèque royale de Belgique. This version was printed by Yale University in 1939 (New Haven: Yale University Press, Yale Romanic Studies, 16).
The version in Alexandrines was the source for a romance in prose by Jehan Wauquelin in 1447 (Paris: éd. L. de Montille, 1880).
Southern French traditions concerning Girart, in which he is called the son of Garin de Monglane, are embodied in the 13th century narrative in rhymed decasyllable verses about the siege of Vienne by Charlemagne in "Girart de Vienne" by Bertrand de Bar-sur-l'Aube. The same traditions also are embraced in "Aspramonte" by Andrea da Barberino, based on the French "chanson" "Aspremont", where he is called Girart de Frete or de Fraite and he leads an army of infidels against Charlemagne.