Place:Principality of Beloozero

Principality of Beloozero or Beloozero Duchy (Russian: Белозерское княжество) was a Russia n principality or duchy, which flourished between the 13th and 15th centuries in the Russian North. In terms of the current administrative division of Russia, the principality was located in the west of Vologda Oblast, around and south of Lake Beloye (White Lake, Russian: Белое озеро).

The principality was detached from the Principality of Rostov in 1238. The town of Beloozero (today's Belozersk) became its capital. Prince Gleb was the first prince of Beloozero (ca. 1238-1278). He increased his standing enormously by marrying Sartaq's daughter. The later rulers of Beloozero could claim a descent from Genghis Khan through this marriage. During Gleb's reign, the duchy's territory embraced the basin of White Lake, the lower streams of the Sheksna River, and Lake Kubenskoye.

The duchy had lost its former significance by the early 14th century. In the first half of the 14th century, Ivan Kalita, the Grand Prince of Moscow, was already appointing namestniks of Beloozero who administered the principality instead of the princes.

In 1389, it was subjugated by Muscovy. Dmitry Donskoy, the Grand Prince of Moscow, handed the principality out to his son Andrey Dmitriyevich. In the end of the 14th century, two influential monasteries were founded at the lands belonging to the principality: Kirillo-Belozersky Monastery in 1397 and Ferapontov Monastery in 1398. The creation was supported by the Moscow princes who considered the foundation of the monasteries as an avenue of the influence of Moscow in the North.

In 1486, the principality, which at the time was a part of the united Principality of Beloozero and Vereya, was formally incorporated into the Grand Duchy of Moscow. Numerous descendants of the ruling Rurikid princes moved to Moscow and continue in a male line to the present. The Belosselsky-Belozersky family was the most notable among them.