Welf I , Duke of Bavaria

M, (1037 - 9 November 1101)
Father-Biological*Alberto Azzo II , Marchese d'Este and of the Lombards b. 997, d. 20 Aug 1097
Mother-Biological*Kunigunde of Altdorf b. c 1020, d. a 1055
Family Lines
Roy Line

Boudreau Line
Last Edited=13 May 2023
Welf I, Duke of Bavaria
     Welf I , Duke of Bavaria was born in 1037.1 He was the son of Alberto Azzo II , Marchese d'Este and of the Lombards and Kunigunde of Altdorf. He was the first member of the Welf branch of the House of Este. In the genealogy of the Elder House of Welf, he is counted as Welf IV.2 When Welf's maternal uncle, Welf, Duke of Carinthia (also known as Welf III), died childless in 1055, Welf inherited his property.2

Welf I , Duke of Bavaria married Ethelinde of Northeim, daughter of Otto I von Northeim , Count in the Rittegau and Richenza of Swabia, in 1062.2 Welf and Ethelinde were divorced circa 1069; When his father-in-law, Duke Otto, had become an enemy of Emperor Henry IV and forfeited his duchy, Welf remained loyal to Henry IV. In compliance with Henry's commands, he repudiated and divorced his wife, Ethelinde.2 During the Investiture Controversy, Welf changed sides turning against the Emperor, supporting Pope Gregory VII as well as lending his support for the election of Rudolf of Rheinfelden in March 1077. Pope and Emperor were superficially reconciled in 1076, but the following year saw them again engaged in active hostilities. Henry, in consequence of these repeated acts of rebellion, declared Welf deposed in his newly acquired duchy. However, supported by his faithful Bavarians and aided by his father in Italy, Welf was able to maintain his place, and openly defy the ban of the Empire in May 1077. Welf joined the discontented princes who supported the standard of Rudolph, at a time when any who refused to follow the pope's direction could expect to be excommunicated by the church—a potent and effective threat in the social and political conditions of the time. However, Gregory died in 1085 and his successors took a less intensive part in the affairs of Germany. Welf, though still adhering to the party of the church, began to relax in his exertions to support Rudolf of Rheinfelden.2 Welf became, in 1070, He was rewarded for his fidelity by being appointed Duke of Bavaria in Otto's stead. This event took place at Goslar in 1070, when the Duchy of Bavaria submitted quietly to the newly made duke, who was the representative of one of the most ancient families in the province. His repudiation of Ethelinde, which could have been considered an act of injustice, does not seem to have been held against him.2

Welf I , Duke of Bavaria married Judith of Flanders , Countess of Northumbria, daughter of Baldwin IV Fair Beard de Lille ~ Count of Flanders and Valenciennes and Eleanor of Normandy, circa 1071.1,3,4,2 In 1099, Welf joined what would become known as the Crusade of 1101, along with William IX of Aquitaine, Hugh of Vermandois and Ida of Austria. His main success was to prevent a clash between fellow Crusaders, who had been pillaging Byzantine territory on their way to Constantinople and the Byzantine emperor's Pecheneg mercenaries. The Crusade itself, entering Anatolia, ended disastrously; after passing Heraclea in September, Welf's Bavarians—like other crusader contingents—were ambushed and massacred by the Turkish troops of Kilij Arslan I, the Seljuq Sultan of Rûm. Welf escaped.2 Welf I , Duke of Bavaria died on 9 November 1101 at Paphos, Cyprus.1,3,4 He was buried on 19 November 1101 at Weingarten Abbey, Weingarten, Bavaria, Germany.1

Compeller's Notes:
Death: Weis (1976) gives his death date as 6 November 1101, while von Redlich (1941) gives his death date as 8 November 1101.3,4

Child of Welf I , Duke of Bavaria and Judith of Flanders , Countess of Northumbria


  1. Stuart, Roderick W. Royalty for Commoners, The Complete Known Lineage of John of Gaunt, Son of Edward III, King of England, and Queen Philippa, Fourth Edition. Baltimore, Maryland: Genealogical Publishing Company, 2002.
  2. Wikipedia: The Free Encyclopedia. Online https://en.wikipedia.org
  3. Weis, Frederick Lewis. Ancestral Roots of Sixty Colonists Who Came to New England Between 1623 and 1650, Fifth Edition. Baltimore, Maryland: Genealogical Publishing Company, 1982.
  4. Von Redlisch, Marcellus Donald Alexander R.. Pedigrees of Some of the Emperor Charlemagne's Descendants, Volume 1. Cottonport, Louisiana: Order of the Crown of Charlemagne, 1941.