Who was known as Ivan the Great?

Ivan the Great, also known as Ivan III, was a pivotal figure in Russian history and played a key role in the unification of Russian lands and the establishment of the Russian state. He ruled from 1462 to 1505 and is credited with ending the dominance of the Mongol Empire over Russia. His victories over the Mongols, particularly at the Great Stand on the Ugra River, significantly contributed to the liberation of Russian territories.

Ivan the Great also initiated a series of reforms that strengthened the Russian monarchy and laid the groundwork for the later expansion of the Russian Empire under his successors. He was the first ruler to use the title "Tsar" (Czar) of All Rus', symbolizing his authority and the centralized power of the state.

While other figures in the choices had significant roles in their respective countries, they do not compare in the context of Ivan the Great’s contributions to Russian history and identity, making the identification as a Russian emperor appropriate and accurate.