The Counts of Stade were members of the Saxony nobility beginning in the 10th century. Stade had developed since the 8th century as a principal center of trade and communications. The Counts of Stade created their domain between the lower Elbe and Weser rivers. They extended their power northwards with the acquisition of Dithmarschen in the 11th century. They became the Margraves of the Nordmark (Northern March) in 1056. There is also a close political and familial relationship between the Counts of Stade and the Counts of Walbeck. The county of Stade and Northern March were replaced by the March of Brandenburg by Henry the Lion, Duke of Saxony, in the 12th century. The family of Counts of Stade is referred to as the House of Udonids.
The principal sources for the Counts of Stade are Widukind of Corvey, the Annals of Fulda, and Thietmar of Merseburg, the great-grandson of Lothar II, Count of Stade, and Lothar I, Count of Walbeck, both killed fighting the Slavs at the Battle of Lenzen.
The Counts of Stade were:
The precise dates of reign are confusing from 1106 until 1135, as the rightful heir Henry IV was not yet of age and the nondynastic Frederich was brought in. The titles of Count of Stade and Margrave of the Nordmark were also not interchangeable during this period, causing further uncertainty.
After the death of Rudolf II in 1144, his brother and successor Hartwig transferred his inheritance to the archbishopric of Bremen in return for a regrant of a life interest, presumably to obtain a powerful protector against the aggression of Henry the Lion. The move was ineffective, as Henry took possession of the lands and captured both Hartwig and the archbishop Adelbero, releasing them only after they agreed to recognize his claim.