Merseburg in the context of "Bishopric of Merseburg"

The Ernestine duchies (German: Ernestinische Herzogtümer), also known as the Saxon duchies (Sächsische Herzogtümer, although the Albertine appanage duchies of Weissenfels, Merseburg and Zeitz were also "Saxon duchies" and adjacent to several Ernestine ones), were a group of small states whose number varied, which were largely located in the present-day German state of Thuringia and governed by dukes of the Ernestine line of the House of Wettin.

In 1800, there were seven such duchies (two held in personal unions with others) that collectively totaled 7,693 square kilometers of territory and were populated by 445,000 inhabitants.

The Marca Geronis or March of Gero was a vast super-march in the middle of the tenth century. It was probably created for Thietmar in the 920s and passed consecutively to his two sons, Siegfried and Gero. On Gero's death in 965 it was divided into five different marches: the Nordmark, Ostmark, Meissen, Zeitz, and Merseburg.

Because Siegfried's and Gero's comital seat was Merseburg, it has sometimes been called the March of Merseburg. However, there is also a Merseburger march which grew out of it after 965. Because the central diocese in his march was Magdeburg, it is sometimes called the March of Magdeburg. Other historians prefer to call it the Saxon Eastern March or Ostmark, but these terms are also applied to another march which grew out of it in 965. Because the Marca Geronis was created simultaneously with the March of Billung to the north, it is sometimes said to be the southern half of the Ostmark. Some historians even call it the "March of Meissen." Within the span of one page, James Westfall Thompson refers to it as both the "Sorben Mark" and the "Thuringian March".

The Leipzig Bay(German: Leipziger Tieflandsbucht) or Leipzig Basin or Saxon Lowland or Saxon Bay is a very flat, originally lakeless and highly fertile plain in Central Germany, in northwestern Saxony and southeastern Saxony-Anhalt, anchored by the foothills of the Harz mountains in the northwest and of the Ore Mountains in the southeast.

This region was originally covered with dense forests and meandering rivers. In the course of urbanization and lignite open pit mining, large areas were deforested and many rivers and streams canalised or diverted. The Leipzig Bay is bounded to the north by the Düben Heath, to the east by the River Elbe, to the south by the Ore Mountain Foreland and the Central Saxon Hills, and by the River Saale to the west. The conurbation formed by the two cities of Leipzig and Halle lies in the centre of the Leipzig Bay. Other important towns are Delitzsch, Eilenburg, Merseburg and Borna.