One or two families
The Babenberg family can be broken down into two distinct groups: 1) The Franconian Babenbergs, the so-called Elder House of Babenberg, whose name refers to Babenburg Castle, the present site of Bamberg Cathedral. Also called Popponids after their progenitor Count Poppo of Grapfeld (d. 839-41), they were related to the Frankish Robertian dynasty and ancestors of the Franconian Counts of Henneberg and of Schweinfurt. 2) The Austrian Babenbergs, descendants of Margrave Leopold I, who ruled Austria from 976 onwards. This second group claimed to have originated from the first, however, scholars have not been able to verify that claim. Today, a direct lineal descent from the Bavarian House of Luitpolding is assumed.
Like the French royal Capetian dynasty, the Elder Babenbergs descended from the Robertians. The earliest known Babenberg count Poppo was first mentioned as a ruler in the Gau of Grabfeld, a historic region in northeastern Franconia bordering on Thuringia, in 819 AD. He may be a descendant of the Robertian count Cancor of Hesbaye.
One of Poppo's sons, Henry, served as princeps militiae under King Louis the Younger and was sometimes called margrave (marchio) and duke (dux) in Franconia under King Charles the Fat of East Francia. He was killed fighting against the Vikings during the Siege of Paris in 886. Another son, Poppo II, was margrave in Thuringia from 880 to 892, when he was deposed by King Charles' successor Arnulf of Carinthia. The Popponids had been favoured by Charles the Fat, but Arnulf reversed this policy in favour of rivalling Conrad the Elder, a member of the Conradine dynasty from the Lahngau in Rhenish Franconia and relative of Arnulf's consort Ota.
The leaders of the Babenbergs were the sons of Duke Henry, who called themselves after their castle of Babenburg on the upper Main river, around which their possessions centred. The city of Bamberg was built around the ancestral castle of the family. The Conradines were led by Conrad the Elder and his brothers Rudolf and Gebhard, probably the sons of Count Udo of Neustria.
The rivalry between the Babenberg and Conradine families was intensified by their efforts to extend their authority in the region of the middle Main, and this quarrel, known as the "Babenberg feud", came to a first head in 892, when King Arnulf deposed Poppo II as Thuringian ruler, appointing Conrad the Elder instead, and installed Conrad's brother Rudolf as Bishop of Würzburg. The struggle intensified at the beginning of the 10th century during the troubled reign of Arnulf's son King Louis the Child. Clashes of arms occurred in 902, when the Conradine laid siege to Babenburg Castle and arrested Adalhard of Babenberg. The next year, Adalhard was executed at the Reichstag of Forchheim; in return, the Babenbergs occupied the city of Würzburg and expelled Bishop Rudolf.
Meanwhile Rudolf's brother Gebhard was appointed Duke of Lotharingia in 903, and had to cope both with revolting nobles and the continuing attacks by Babenberg forces. Both sides met in the battle of Fritzlar on 27 February 906, where the Conradines won a decisive victory, although Conrad the Elder fell in the battle. Two of the Babenberg brothers were also killed. The third, Adalbert, was summoned before the imperial court by the regent Archbishop Hatto I of Mainz, a partisan of the Conradines. He refused to appear, held his own for a time in his castle at Theres against the king's forces, but surrendered in 906, and in spite of a promise of safe-conduct by Hatto was beheaded.
Conrad the Younger became Duke of Franconia in 906 and King of East Francia (as Conrad I) in 911, while the Babenbergs lost their influence in Franconia.