Mongol control of Russia helped to ___.

The Mongol conquest of Kievan Rus' was part of the Mongol invasion of Europe, in which the Mongol Empire invaded and conquered Kievan Rus' and other Russian principalities in the 13th century AD, destroying numerous cities, including Ryazan, Kolomna, Moscow, Vladimir and Kiev.[4][5]

The campaign was heralded by the Battle of the Kalka River in May 1223, which resulted in a Mongol victory over the forces of several Rus' principalities. The Mongols retreated, having gathered their intelligence which was the purpose of the reconnaissance-in-force. A full-scale invasion of Rus' by Batu Khan followed, from 1237 to 1242. The invasion was ended by the Mongol succession process upon the death of Ögedei Khan. All Rus' principalities were forced to submit to Mongol rule and became vassals of the Golden Horde empire, some of which lasted until 1480.

The invasion, facilitated by the beginning of the breakup of Kievan Rus' in the 13th century, had incalculable ramifications for the history of Eastern Europe, including the division of the East Slavic people into three separate nations: modern-day Russia, Ukraine and Belarus,[6] and the rise of the Grand Duchy of Moscow.

Explanation:

this forms a narrow, steep sided inlet (sometimes deeper than 1300 metres) connected to the sea. the terminal moraine pushed down the valley by the glacier is left underwater at the fjord’s entrance, causing the water at the neck of the fjord to be shallower than the main body of the fjord behind it.