[jweber.ged]
The following information is from a post-em by Curt Hoffeman, curt_hofemann@yahoo.com:
The earliest known ancestor of the Babenbergs was one Poppo, who early in the 9th century was count in Grapfeld, in the area between modern Hesse and Thuringia. One of his sons, Henry, sometimes called count of the march and duke in Franconia, fell fighting against the Normans in 886; another, Poppo, was count of the march in Thuringia from 880 to 892, when he was deposed by the German Carolingian king Arnulf of Carinthia. The family had been favoured by the emperor Charles the Fat, but Arnulf reversed this policy in favour of the rival family of the Conradines.
The leaders of the Babenbergs were the three sons of Duke Henry, who called themselves after their castle of Babenberg on the upper Main, round which their possessions centred.
The rivalry between the two 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 head at the beginning of the 10th century during the troubled reign of the German king Louis the Child. Two of the Babenberg brothers were killed, and the survivor, Adalbert was summoned before the imperial court by the regent Hatto I, Archbishop 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 was beheaded. [Ref: Wikipedia (who slightly rephrased it from the 1911 Encyclopedia Britannica online at: http://92.1911encyclopedia.org/B/BA/BABENBERG_FAMILY_.htm]