Prince Oleg of Kyiv, extended his rule over this territory known as the Ponizie, or "lowlands." These lowlands later became a part of the Rus' principalities of Volhynia, Kyiv, and Galicia. In the 13th century, Bakota served as its political and administrative centre. During that time, the Mongols plundered Ponizie; Algirdas (Olgierd), prince of the Grand Duchy of Lithuania, freed it from their rule following his victory against the Golden Horde in the Battle of Blue Waters of 1362, annexing it to his own territories under the name of "Podolia", which has the same meaning as Ponizie. Polish colonisation began in the 14th century.