Russian principality, separated from the Vladimir-Suzdal’ Principality in 1238. Its principal city was Beloozero (present-day Belozersk).
The first prince was Gleb Vasil’kovich (c. 1238–78). During his reign the Beloozero Principality encompassed the Lake Beloe basin, the lower course of the Sheksna River, and Lake Kubenskoe. An important development in the Beloozero Principality was the ownership of land by the monasteries, which seized many state-owned volosts (small rural districts), as well as those belonging to the nobility, and almost all patrimonial lands. During the first half of the 14th century the Beloozero Principality lost its independence; in 1389 it became a part of the Grand Principality of Moscow and, beginning in 1486, a district of the Russian Empire.