Hugo II von Tübingen, Graf von Bregenz, Montfort & Sigmaringen

The Counts of Montfort were originally a branch of another Swabian noble family, the Counts Palatine of Tübingen. Hugo II of Tübingen (d. 1182) married Elizabeth of Bregenz, and through her, Hugo would take ownership over the former territories of the Counts of Bregenz, including Bregenz itself, Montfort, and Sigmaringen, making him a dominant power in the region. His marriage to Elizabeth would also provide him with close family ties to Emperor Frederick I Barbarossa and the Welfs (like Barbarossa and Henry the Lion, Elizabeth was a grandchild of the Welf duke Henry IX "the Black" of Bavaria).
Upon the death of Hugo II, the majority of the former Bregenz territories would go to his second son, Hugo III (d.1228/1230), who after about 1200 would style himself "Hugo of Montfort". His territories as count included Raetia Curiensis, Tettnang, Bregenz, Feldkirch, Sonnenberg, Werdenberg, and Sargans. The new House of Montfort would adopt the arms of the County Palatine of Tübingen, but the Montfort arms would feature a red gonfalon on a silver shield instead of a gold one.

https://en.wikipedia.org/wiki/Counts_of_Montfort