Samogitia

Samogitia (Lithuanian: Žemaitija), lying between Prussia and Livonia, two lands already in the hands of the German Crusading knights, was a particular object of German expansion.

…his leadership included Lithuania proper, Samogitia, and much of Belorussia. In 1250 or 1251 Mindaugas accepted baptism from the Livonian Knights, thus easing western pressure against his state from the Teutonic and Livonian Knights and from Daniel of Halich-Volynia. In 1253 he received a royal crown from Pope Innocent IV.

…seeking to master eastern Lithuanian Samogitia (Polish: Żmudź)—on the pretext of Christianizing its inhabitants—led to the great war in which Poland and Lithuania joined forces. The result was a crushing defeat of the Knights at Tannenberg (Grunwald) in 1410. The victory had no immediate sequel, for the Knights ceded only…