Hermann III von Öhningen, duke of Swabia

http://fmg.ac/Projects/MedLands/SWABIA.htm#Mathildedied1031

He was Duke of Swabia (1003-1012). He had no issue.

From Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Herman_III,_Duke_of_Swabia)

Hermann III (died April 1, 1012) was Duke of Swabia from 1003 until 1012. The son of Hermann II, he was a member of the Conradines. His mother, Gerberga of Burgundy, was a granddaughter of Louis IV of France and was a descendent of Charlemagne.[1]

Hermann's reign as duke was effectively controlled by the King of Germany, Henry II. At the time of his ascension, Hermann was still a minor, and Henry disliked the Conradines; Hermann II had opposed his election as king in 1002. Henry's control over Swabia was still present when Hermann died in 1012. Since he died childless, the male line of the Conradines of Swabia came to an end. Henry selected Ernest to succeed him; two years later, Ernest married Hermann's sister Gisela of Swabia.