First partition of Mecklenburg

During its history, the state of Mecklenburg has been repeatedly partitioned into various successor states (lordships, duchies, grand duchies). Modern historians distinguish three main Partitions of Mecklenburg:

The first partition of Mecklenburg was carried out in 1234 by the heirs of Henry Borwin II, Lord of Mecklenburg. It was a result of the Realteilung (partition due to partible inheritance) of the territory into four Herrschaften (lordships) or Fürstentümer (principalities): Mecklenburg, Parchim (later Parchim-Richenberg), Werle and .

The effects of the first partition lasted until 1471, when the territories were reunited by Henry IV, Duke of Mecklenburg through inheritance.

The second partition of Mecklenburg took place in 1621 as a result of the Fahrenholzer Vertrag: a partition agreement, resulting in the Realteilung into the Duchies of Mecklenburg-Schwerin and Mecklenburg-Güstrow. Although this division already existed (with interruptions) after the death of Henry IV in 1477 and again after 1520 (after the Neubrandenburger Hausvertrag (New Brandenburg House Contract)), it was only in the form of an allocation of Ämter (singular Amt; a type of administrative division), while general governance remained unified.

In the agreement, Adolf Frederick I received the princely state of Schwerin, while his brother John Albert II received the land centred on Güstrow.

...
Wikipedia