Russian Empire
Though the Empire was only officially proclaimed by Tsar Peter I following the Treaty of Nystad (1721), some historians would argue that it was truly born either when Ivan III of Russia conquered Veliky Novgorod in 1478, or when Ivan the Terrible conquered the Khanate of Kazan in 1552. According to another point of view, the term "Tsardom", which was used after the coronation of Ivan IV in 1547, was already a contemporary Russian word for empire.
List of Russian explorers
From the 11th century on, a group of Russians which settled the shores of the White Sea and became known as Pomors ("seaside-dwellers") began navigating in the freezing seas of the Arctic Ocean, gradually developing the first icebreaking ships known as kochi. As early as the 11th century Russians from the Novgorod Republic had occasionally penetrated into Siberia. In the 14th century the Novgorodians started exploring the Kara Sea and the West-Siberian river Ob. Russians were among those rare medieval Europeans who traveled deep into Central Asia or visited South Asia. Prince Yaroslav II of Vladimir and his sons Alexander Yaroslavich Nevsky and Andrey Yaroslavich traveled to Karakorum, the capital of the Mongolian Empire in the 1240s, while Afanasy Nikitin, a merchant from the Principality of Tver, traveled to Persia and India in "A Journey Beyond the Three Seas" in 1466-1472.