On December 29, 1543, Ivan the Terrible arrived — with the summary execution of hated boyar Andrei Shuisky (Shuysky). Call it Ivan’s rite of passage. The 13-year-old Ivan IV had technically “ruled” Russia since toddlerhood, when his father died suddenly in the prime of life. But in reality, the “ruler” was not the master of his domain. The powerful boyar nobles ran roughshod during his minority, scrapping for power, poisoning off his mother,* and behind the Kremlin’s closed doors overtly treating the kiddo’s regal person like a redheaded stepchild. “What evil did I suffer at [the boyars’] hands!” Ivan later...