"Ivan IV Vasilyevich (Russian: Ива́н Васи́льевич; 25 August 1530 – 28 March [O.S. 18 March] 1584), commonly known as Ivan the Terrible (Russian: Ива́н Гро́зный (help·info) Ivan Grozny; "Ivan the Formidable" or "Ivan the Fearsome", Latin: Ioannes Severus), was the Grand Prince of Moscow from 1533 to 1547 and the first Tsar of Russia from 1547 to 1584.
Ivan was the son of Vasili III, the Rurikid ruler of the Grand Duchy of Moscow and was appointed Grand Prince when he was three years old after his father's death. A group of reformers united around the young Ivan and known as the "Chosen Council", declared him tsar (emperor) of All Rus' in 1547 at the age of 16 and established the Tsardom of Russia with Moscow as the predominant state. Ivan's reign was characterised by Russia's transformation from a medieval state to an empire under the tsar but at an immense cost to its people and its broader, long-term economy." - (en.wikipedia.org 02.01.2021)