Originally a noble clan in the Frankish alliance ruling a Lotharingian county. During the 8th century the Welfs moved to Lake Constance, ruled South Bavaria and Suebia, Burgundy and Carinthia. In the 12th century they struggled for the imperial crown with the Staufian clan.
Known representatives are count Welf (+ 825), Henry the Lion (Heinrich der Löwe), who was beaten by his cousin Frederic I (Friedrich I), and Otto IV (1198 king, 1209 emperor).