The Lower Saxon Circle (German: Niedersächsischer Reichskreis) was an Imperial Circle of the Holy Roman Empire. It covered much of the territory of the medieval Duchy of Saxony (except for Westphalia), and was originally called the Saxon Circle (German: Sächsischer Kreis) before later being better differentiated from the Upper Saxon Circle by the more specific name.
The first plans for a Lower Saxon Circle originate from Albert II of Germany in 1438. An Imperial Saxon Circle was formally created in 1500, but in 1512 it was divided into an Upper Saxon and Lower Saxon Circle. The division was only codified in 1522, and it took a while before the separation was completely implemented by the Imperial Chamber Court. Furthermore, the first mention of an Upper Saxon Circle, a Lower Saxon Circle or the Netherlands occurred much later on. The term Lower Saxony (Niedersachsen) was first used only in 1548.
The Lower Saxon Circle included the easternmost part of current Lower Saxony, the northernmost part of Saxony-Anhalt (excluding the Altmark), Mecklenburg, Holstein (excluding Dithmarschen), Hamburg, Bremen, in addition to small areas in Brandenburg and Thuringia. For the most part it was a continuous territory with the exception of small enclaves like Halle and Jüterbog. Nordhausen and Mühlhausen were also areas outside the continuous portion of the imperial circle. Within the circle was the Archbishopric of Verden, which was in personal union with the Archbishopric of Bremen since 1502. The Counties of Schaumburg and Spiegelberg were also part of the personal union, but they were not a part of the Lower Saxon Circle.
By the downfall of the Holy Roman Empire, the circle had 2,120,00 inhabitants and an area of 1,240 square miles. With respect to religion, almost all the citizens were Protestant. The exception was the partially Catholic Bishopric of Hildesheim.
A large part of the circle was made up of territories ruled by the House of Welf. With the Protestant Reformation the newly converted Archbishopric of Magdeburg was ruled from 1513 by administrators from the Brandenburg line of the House of Hohenzollern. Also, in 1648 the Bishopric of Halberstadt was given to the Margraviate of Brandenburg. The Archbishopric of Bremen, after the Reformation, was ruled by Danes and Swedes, and after 1715 by the House of Welf. Through the Duchy of Oldenburg, the king of Denmark became a prince of the imperial circle. Also as a result of their possessions in the imperial circles, the kings of Prussia, Sweden, and Great Britain, who governed the Electorate of Brunswick-Lüneburg, became princes of the empire. Out of the entire empire, the Lower Saxon Circle was ruled the most by foreign kings. Regardless of this, the House of Welf's strong position with the Lower Saxon Circle prevented the dukes of Mecklenburg and the kings of Denmark from completely dominating.
The circle was made up of the following states:
|Name||Type of entity||Comments|
|Blankenburg||County||Established in 1123, from 1599 held by the Dukes of Brunswick-Wolfenbüttel, raised to Principality in 1703,|
|Bremen||Prince-Archbishopric||Established in 787 by Charlemagne, secularized in 1648 as Duchy of Bremen, fief of the Swedish Crown, ceded to Hanover in 1719|
|Bremen||Imperial City||From 1186|
|Brunswick-Lüneburg||Duchy||Undivided between 1235–1269, thus it existed as single territory only before the establishment of imperial circles. Thereafter General name for all Welf territories in the region.|
|Calenberg||Principality, Duchy||Subdivision of Brunswick-Lüneburg from 1494, united with Celle in 1705 to form Hanover, containing all of Brunswick except Wolfenbüttel|
|Gandersheim||Prince-Abbacy||Established in 852 by Duke Liudolf of Saxony, Imperial immediacy confirmed by King Henry the Fowler in 919, contested by Brunswick-Wolfenbüttel|
|Goslar||Imperial City||From 1290|
|Grubenhagen||Principality||Subdivision of Brunswick-Lüneburg from 1291 until 1596|
|Halberstadt||Prince-Bishopric||Established by Charlemagne in 804, secularized in 1648 as Principality of Halberstadt held by Brandenburg|
|Hamburg||Imperial City||From 1189|
|Hildesheim||Prince-Bishopric||Established in 815 by Louis the Pious|
|Holstein||Duchy||Established in 1474, held by the Danish Royal House of Oldenburg, from 1648 residence in Glückstadt|
|Holstein-Gottorp||Duchy||Subdivision of Holstein from 1544 until 1773|
|Lübeck||Prince-Bishopric||Established in 1160 by Henry the Lion|
|Lübeck||Imperial City||From 1226|
|Lüneburg||Principality||Subdivision of Brunswick-Lüneburg from 1269 until 1705|
|Magdeburg||Prince-Archbishopric||Established in 955 by Otto I, secularized in 1680 as Duchy of Magdeburg, held by Brandenburg|
|Mecklenburg-Schwerin||Duchy||Established in 1352|
|Mecklenburg-Güstrow||Duchy||Subdivision of Mecklenburg-Schwerin from 1520 until 1552, again from 1621 until 1695|
|Mecklenburg-Strelitz||Duchy||Subdivision of Mecklenburg-Schwerin from 1701|
|Mühlhausen||Imperial City||From 1251|
|Nordhausen||Imperial City||From 1220|
|Rantzau||County||Established in 1650, held by the Danish Royal House of Oldenburg from 1734|
|Ratzeburg||Prince-Bishopric||Established in 1154 by Henry the Lion, secularized in 1648 as Principality of Ratzeburg, held by the Dukes of Mecklenburg, Mecklenburg-Strelitz from 1701|
|Regenstein||County||From about 1160, united with Blankenburg in 1368, held by the Dukes of Brunswick-Wolfenbüttel from 1599|
|Saxe-Lauenburg||Duchy||Established in 1296, fell to the Dukes of Brunswick-Calenberg in 1689|
|Schwerin||Prince-Bishopric||Established in 1154 by Henry the Lion, residence at Bützow from 1239, secularized in 1648 as a principality held by the Dukes of Mecklenburg-Schwerin|
|Wolfenbüttel||Principality||Subdivision of Brunswick-Lüneburg from 1269, became Duchy of Brunswick in 1815|