Short answers, pulled from the story.
Ivan IV became the first ruler to officially use the title tsar on the 16th of January 1547. This coronation in Moscow marked the official birth of the Tsardom of Russia and signaled a shift toward absolute power modeled after Byzantine emperors.
The oprichnina was a private domain established by Ivan IV in 1565 that allowed him to target powerful boyar families who opposed his policies. Agents under his command executed nobles, confiscated land, and instilled fear throughout the population until he abandoned the system in 1572.
Feodor died without heirs in 1598, which caused the end of the Rurik Dynasty and plunged Russia into the Time of Troubles. Boris Godunov seized power temporarily before multiple claimants vied for the throne while foreign powers intervened militarily.
The Sobornoye Ulozhenye formalized serfdom across Russia in 1649 by granting landlords complete authority over peasants who could no longer move freely between estates. Runaway individuals were declared fugitives subject to arrest, binding most agricultural workers permanently to their plots.
Peter the Great transformed Russia from an isolated state into a major European power after becoming ruler independently in 1696. He traveled incognito across Western Europe to study advanced technologies and military strategies before implementing aggressive modernization efforts that culminated in victory during the Great Northern War in 1721.