History of Russia
The war ended in 1721 when an exhausted Sweden sued for peace with Russia. Peter acquired four provinces situated south and east of the Gulf of Finland, thus securing his coveted access to the sea. There, in 1703, he had already founded the city that was to become Russia's new capital, Saint Petersburg, as a "window opened upon Europe" to replace Moscow, long Russia's cultural center. Russian intervention in the Commonwealth marked, with the Silent Sejm, the beginning of a 200-year domination of that region by the Russian Empire. In celebration of his conquests, Peter assumed the title of emperor, and the Russian Tsardom officially became the Russian Empire in 1721.
History of the Eastern Orthodox Church
Russia lay under Mongol rule from the 13th through the 15th century. The Mongol invasion of Rus of 1237–1242AD lead to what is called the Tatar period in Russian history. This period lead to great calamity for the internal structure of Russia. Much of Russia was ruled by Mongols and Russian Princes (of whom had limited power).
The eventual end of the reign of the Golden Horde is said to have begun with the Battle of Kulikovo 8 September 1380. Which involves the famous Orthodox legend of Monk and Russian champion Alexander Peresvet and his death that mark the battle's beginning. The final pseudo-battle or face off that ended Mongol rule in Russia was the Great stand on the Ugra river in 1480AD. The death toll (by battle, massacre, flooding, and famine) of the Mongol wars of conquest is placed at about 40 million according to some sources.