In 954, Margrave Gero of the Saxon Eastern March (the marca Geronis), aided by Holy Roman Emperor Otto I's son-in-law, Conrad of Lorraine, launched a successful campaign to subdue the Ukrani, who had come in reach of the Empire after the 929 Battle of Lenzen.

After the 983 revolt of the Obodrites and Liutizians, the area became independent again, yet remained under permanent military pressure, especially from Poland and the Holy Roman Empire.

In 1172 Pomeranian dukes, vassals of the Duchy of Saxony, formerly of Poland, and later of Denmark and the Holy Roman Empire, controlled the area.

The early centers of the territory were the Seehausen (Gramzow) Premonstratensian monastery and the city of Prenzlau, developed and granted German town law by Barnim I, Duke of Pomerania, in 1234.

[3] In late 1320, a portion of the Uckermark was occupied by Saxe-Wittenberg, whereas the northermost parts with Prenzlau and Pasewalk remained under Pomeranian control.

The first Peace of Prenzlau of 3 May 1448 established Brandenburg's control over most of the territory, except for the northern Pasewalk and Torgelow region, which was to remain in Pomerania and is not considered to be a part of Uckermark anymore.

Though another Brandenburgian-Pomeranian war was fought in the area in the 1460s, Brandenburg's possession of most of the Uckermark was confirmed again in a second Peace of Prenzlau on 30 July 1472, which was renewed on 26 June 1479.

Frederick William, the Great Elector, invited large numbers of French Huguenots to resettle the Uckermark and his other territories by announcing the Edict of Potsdam.