While the oldest endonyms of the Grand Duchy of Moscow used in its documents were Rus' (Russian: Русь) and the Russian land (Russian: Русская земля), a new form of its name, Rusia or Russia, appeared and became common in the 15th century. In the 1480s Russian state scribes Ivan Cherny and Mikhail Medovartsev mention Russia under the name Росиа, Medovartsev also mentions "the sceptre of Russian lordship (Росийскаго господства)". In the following century Russia co-existed with the old name Rus' and appeared in an inscription on the western portal of the
Transfiguration Cathedral of the Spaso-Preobrazhensky Monastery in Yaroslavl (1515), on the icon case of the Theotokos of Vladimir (1514), in the work by Maximus the Greek, the Russian Chronograph written by Dosifei Toporkov (?–1543/44) in 1516–22 and in other sources.
In 1547, Ivan IV assumed the title of “Tsar and Grand Duke of all Rus'” (Царь и Великий князь всея Руси) and was crowned on 16 January, thereby turning the Grand Duchy of Moscow into Tsardom of Russia, or "the Great Russian Tsardom", as it was called in the coronation document, by Constantinople Patriarch Jeremiah II and in numerous official texts, but the state partly remained referred to as Moscovia (English: Muscovy) throughout Europe, predominantly in its Catholic part, though this Latin term was never used in Russia. The two names "Russia" and "Moscovia" appear to have co-existed as interchangeable during the later 16th and throughout the 17th century with different Western maps and sources using different names, so that the country was called "Russia, or Moscovia" (Latin: Russia seu Moscovia) or "Russia, popularly known as Moscovia" (Latin: Russia vulgo Moscovia). In England of the 16th century, it was known both as Russia and Muscovy. Such notable Englishmen as Giles Fletcher, author of the book Of the Russe Common Wealth (1591), and Samuel Collins, author of The Present State of Russia (1668), both of whom visited Russia, were familiar with the term Russia and used it in their works. So did numerous other authors, including John Milton, who wrote A brief history of Moscovia and of other less-known countries lying eastward of Russia, published posthumously, starting it with the words: "The Empire of Moscovia, or as others call it, Russia..."
In the Russian Tsardom, the word Russia replaced the old name Rus' in official documents, though the names Rus' and Russian land were still common and synonymous to it, and often appeared in the form Great Russia (Russian: Великая Россия), which is more typical of the 17th century, whereas the state was also known as Great-Russian Tsardom (Russian: Великороссийское царствие).
According to prominent historians like Alexander Zimin and
Anna Khoroshkevich, the continuous use of the term Moscovia was a result of traditional habit and the need to distinguish between the Muscovite and the Lithuanian part of the Rus', as well as of the political interests of the Polish-Lithuanian Commonwealth, which competed with Moscow for the western regions of the Rus'. Due to the propaganda of the Commonwealth, as well as of the Jesuits, the term Moscovia was used instead of Russia in many parts of Europe where prior to the reign of Peter the Great there was a lack of direct knowledge of the country. In Northern Europe and at the court of the Holy Roman Empire, however, the country was known under its own name, Russia or Rossia. Sigismund von Herberstein, ambassador of the Holy Roman Emperor in Russia, used both Russia and Moscovia in his work on the Russian tsardom and noted: "The majority believes that Russia is a changed name of Roxolania. Muscovites ("Russians" in the German version) refute this, saying that their country was originally called Russia (Rosseia)". Pointing to the difference between Latin and Russian names, French captain Jacques Margeret, who served in Russia and left a detailed description of L’Empire de Russie of the early 17th century that was presented to King Henry IV, stated that foreigners make "a mistake when they call them Muscovites and not Russians. When they are asked what nation they are, they respond 'Russac', which means 'Russians', and when they are asked what place they are from, the answer is Moscow, Vologda, Ryasan and other cities". The closest analogue of the Latin term Moscovia in Russia was “Tsardom of Moscow”, or “Moscow Tsardom” (Московское царство), which was used along with the name "Russia", sometimes in one sentence, as in the name of the 17th century Russian work On the Great and Glorious Russian Moscow State (Russian: О великом и славном Российском Московском государстве).