Answer:
The resurgence of russa under Ivan IV began in the middle of the 1500s CE. Because he was named Tsar in 1947 assuming absolute power.
Step-by-step explanation:
Ivan IV was named first Tsar in 1947 because both his parents had died and the different Noble factions and clans moved to seek power, but after a campaign of justice and order he managed to be named Great Prince of Russia, to govern over them and assume absolute control by means of violence and increasing his impact or execution to make them fear him and prevent another move from them. Ivan expanded the relevance and power of Moscow all over Europe, fought and minimized the Mongols and unified territories to strengthen his monarchy.