The second half of the 15th century. Duchy of Moscow Ivan III takes an offer by ambassadors from Rome to marry princess Zoe of an ancient Byzantine Palaiologos family. He sends a voivode Khromoy and a monetary master Ivan Fryazin to Rome, who bring Zoe to Moscow, where she takes a new name after rebaptism – Sophia. She did not meet the expectations of the Pope to expand an influence of the Catholic Church in Russia. The attempts to send emissaries with the aim of urging Sophia to follow the line of Rome and further killing her end in failure. The most notable moments of Ivan III's rule are shown, including: the war with Novgorod Republic, disagreement and further peace with Ivan's brothers, victory over Golden Horde, and also opposition of Sophia with a wife of Ivan's elder son Elena.
