He detested Russia's boyars

One of the interesting facts about Ivan the Terrible is that he detested Russia's boyars. Despite the devastation caused by the Great Fire of 1547, Ivan's reign began with peaceful reforms and modernization. Ivan revised the law code, establishing the Sudebnik of 1550, establishing a standing army (the streltsy), establishing the Zemsky Sobor (the first Russian parliament of feudal estates) and the council of the nobles (known as the Chosen Council), and confirming the Church's position with the Council of the Hundred Chapters (Stoglavy Synod), which unified the rituals and ecclesiastical regulations He established local self-government in rural areas dominated by the state peasantry, mostly in northeastern Russia.

Ivan endured a near-fatal sickness in 1553 and was assumed to be unable to recover. Ivan had ordered the boyars to take an oath of fealty to his eldest son, who was a newborn at the time, while on his believed deathbed. Many boyars declined because they believed the tsar's health was too bad for him to live. That infuriated Ivan and increased his mistrust of the boyars. Assassinations and terrible retaliation followed, including those of Metropolitan Philip and Prince Alexander Gorbatyi-Shuisky. Saint Philip II of Moscow was a Russian Orthodox monk who rose to the position of Metropolitan of Moscow during Ivan the Terrible's reign. He was one of just a few Metropolitans who openly defied imperial authority, and it is largely assumed that the Tsar had him executed for it. In the Eastern Orthodox Church, he is regarded as a saint and martyr. Prince Alexander Borisovich Gorbatyi-Shuisky was undoubtedly Ivan the Terrible's most celebrated and popular general. Gorbatov, in Nizhny Novgorod Oblast, bears his name. He was the last scion of the powerful Shuisky family's junior branch. His father was one of Vasily III's most effective generals, but Alexander quickly surpassed him. In 1544, he was made a boyar, and in 1547, he led the Russian army against the Khanate of Kazan.