Crowned as the first tsar of Russia, he controlled the largest nation on Earth but in his later years, executed thousands and, in rage, killed his own son.
In 1547, Ivan IV, grandson of Ivan the Great, was crowned the first czar of all Russia (the term czar was derived from caesar) in the Kremlin's Uspensky Cathedral. In addition, Moscow became the capital of the Holy Russian Empire.
In the same year, Ivan married Anastasia Romanov. He married several more times after her death in 1560, but this first marriage seems to have been the happiest. The Romanov dynasty ruled Russia from 1613 to 1917, and traces its claim to the throne through Anastasia's brother, Nikitu.
Ivan ruled with a deep-seated paranoia and ruthlessness; it's said that he gouged out the eyes of the architects who built St. Basil's so that a cathedral of such beauty could never again be created.
The czar's power became absolute when Ivan the Terrible succeeded in conquering the remaining independent principalities, such as Siberia. The state also assigned a master to the peasants who worked the lands around an estate, setting in stone the system of serfdom.
Ivan organised the Streltsy (members of the army elite) to govern his districts and the Oprichniki (the first police force) to suppress boyar (ruling-class nobles) rebellion.
He confiscated the property of the boyars and granted state property to those who served him. Since his soldiers were tenured to the state for life, their land grants became hereditary and they formed a new ruling elite.
In 1582, after the Livonian War with Poland and Sweden, Russia lost her far northern territories and her access to the Baltic. In the same year, the czar also killed his son, Ivan, in a fit of rage.
When Ivan the Terrible died in 1584, Russia was left in a state of almost total political and economic ruin.