Grand Prince Alexander Nevsky played a key role in defending Rus from the Catholic West. In the western direction, he proved himself as a warrior, while in relations with the East, he acted as a diplomat, managing to preserve Russian lands during the Tatar-Mongol invasion. The Russian Orthodox Church canonized him as a saint.

The 13th century was one of the most challenging periods in Russian history. The princely feuds destroyed the unity of the political, economic, spiritual, and cultural space of the country. In 1223, the Mongol-Tatars approached the eastern borders. Alexander Yaroslavich, a member of the Rurik dynasty, was born in 1221. His father, Prince Yaroslav, soon took the throne of Kiev and was supposed to maintain order in the Russian lands. In 1228, Yaroslav left the underage Alexander and his older brother Fyodor to rule in Novgorod under the guardianship of the steward Yakun and the voivode Fyodor Danilovich. Despite Yaroslav's neglect of Novgorod, in 1230, the Novgorodians invited him again, hoping he would leave his sons to rule. In 1233, Fyodor died, and 12-year-old Alexander participated for the first time in a military campaign against Derpt (Yuriev) under his father's banner. The campaign was unsuccessful, and the devastation of North-Eastern Rus by Batu in 1237-1238 intensified the actions of the Livonian Order and Sweden. In 1240, the Swedes landed at the mouth of the Neva, and the knights of the Livonian Order besieged Pskov. The Swedish leader sent Alexander a bold message, but the prince, with a small retinue, suddenly attacked the Swedes and achieved a crushing victory. This victory made him a hero. Before the battle, the Izhora elder Pelgusius had a vision of boats with Russian warriors and saints Boris and Gleb floating down the Neva. However, the Novgorodians believed the prince had become proud and expelled him. After the capture of Pskov by the Livonians, the Novgorodians changed their minds, and in 1241, Alexander became their prince again. On April 5, 1242, on Lake Chud, the Novgorodians and Suzdal troops defeated the army of the Livonian Order, halting the advance of their western neighbors. In the Ice Battle, 50 knights were captured, which was unprecedented. In 1245, the Lithuanian prince Midovings invaded Russian lands, but upon learning of Alexander's approach, his army fled. The Novgorodians caught up and defeated the Lithuanians. In five years, Alexander expanded Novgorod's territories, reclaiming part of Latgalia from the Livonian Order. In 1246, his father Yaroslav was poisoned in Karakorum, and in 1247, Alexander went to Batu, who welcomed him warmly and became his adoptive father. Alexander Nevsky ruled Rus until 1263. On his way home after a trip to Karakorum, he died, possibly also poisoned.