The first Russian ruler to take the title of tsar, for 10 points, identify this man who gained his nickname for his fearsome acts.
His reign saw his armies emerge victorious at the Battle of Ergeme in the disastrous Livonian War. He had the head of the church, Filipp Kolychev, and Prince Vladimir Staritsky executed during a period known as oprichnina. He killed his son and heir apparent accidentally, and was hence succeeded by the weak Feodor I, whose reign saw the rise to power of Boris Godunov. The first Russian ruler to take the title of tsar, for 10 points, identify this man who gained his nickname for his fearsome acts.
His reign saw his armies emerge victorious at the Battle of Ergeme in the disastrous Livonian War.
{Ivan IV} Vasilyevich or {Ivan} the {Terrible} or {Ivan Groznyi}