The extinction of the counts of Lenzburg in 1173 strengthened the Zähringer position south of the Rhine, but their territorial expansion was halted following their support of the Welfs in the unsuccessful feud against Conrad III of Germany during 1138–1152. This frustrated their ambitions to carve out a contiguous territorial duchy wedged between Swabia and Burgundy, in spite of late attempts on the part of Berthold V to increase his territorial sway (who as late as 1210 aimed at receiving the jurisdiction over St. Gallen).
The extinction of the counts of Lenzburg in 1173 strengthened the Zähringer position south of the Rhine but their territorial expansion was halted following their support of the Welfs in the unsuccessful feud against Conrad III of Germany during 1138–1152. This frustrated their ambitions to carve out a contiguous territorial duchy wedged between Swabia and Burgundy in spite of late attempts on the part of Berthold V to increase his territorial sway (who as late as 1210 aimed at receiving the jurisdiction over St. Gallen)