Siegfried (archbishop of Bremen)

They altogether testified, that Bremen's Archbishop Hartwig, Count of Stade confirmed to have received a donation of Siegfried's paternal grandmother Eilika in Paulinzell.

Henry the Lion, Duke of Saxony, Westphalia and Angria and of Bavaria, was an ambitious man, striving for more independence and rejecting the imperial overlordship.

He gained strong allies through marriage with Matilda Plantagenêt, the daughter of Henry II of England and Eleanor of Aquitaine and sister of Richard Lionheart, and by way of alliance with Prince Pribislav of Mecklenburg and Duke Casimir I of Pomerania.

Henry's paternal cousin[1] Emperor Frederick I Barbarossa, House of Hohenstaufen, steadily had to assert himself against his princely vassals and the Roman Catholic Church.

Siegfried's Ascanian clan, domiciled at the middle Elbe river and then led by Albert the Bear, a maternal cousin[2] of Henry the Lion, also strove for more power and territories to conquer westwards from Saxon and eastwards from Slavic rulers.

[3] The capitulars, opposing Henry the Lion and his claim to the County of Stade, voted for Siegfried, while the Guelphic party elected Otbertus, the dean of the Chapter.

Henry's loyal vassal, Gunzelin of Hagen, first Count of Schwerin, took martial actions against anti-Guelphic partisans, provoking an upheaval in Bremen.

Frederick I aligned himself with Henry the Lion, in order to ascertain his loyalty, and appointed the Bremian capitular provost Baldwin I to the see, Alexander III confirmed that.

Through the influence of his friend, Wichmann of Seeburg, Archbishop of Magdeburg, in 1173 the Brandenburgian Chapter elected Siegfried the new Prince-Bishop of Brandenburg, succeeding the late Wilmar.

Wichmann visited Frederick I in Italy in order to fathom in how far Siegfried's claim to the Bremian See could be enforced – e.g. in the scope of the Peace of Venice.

In 1179 Siegfried attended the Third Council of the Lateran in Rome, while the Bremian Chapter elected another Guelphic partisan, Berthold, for Archbishop.

The Gelnhausen Diet (1180) confirmed Siegfried as Archbishop upgraded part of the diocesan territory to form the Prince-Archbishopric of Bremen of imperial immediacy.

Since the deposed Henry the Lion had entrenched in his last Saxon stronghold, the city of Stade, Otto I and Bernhard III militarily supported their brother Siegfried to de facto gain the power in all the Prince-Archbishopric.

In his new position of Duke of Saxony he held the Land of Hadeln around Otterndorf, south of the river Elbe right opposite of Ditmarsh on the north bank.

In 1183, some canons of Bremen's Cathedral formed a conspiracy against Siegfried, blaming him at Pope Lucius III to be a too secular clerk.