After a fourteen-year boyar regency, Ivan the Terrible was crowned tsar and married to Anastasiia Romanova. In 1553 the tsar’s illness led to a succession crisis: some boyars hesitated to swear loyalty to his infant son. The birth of two more sons, Ivan and Fyodor, guaranteed an heir. As the oldest boy grew up, Tsar Ivan brought him to meetings with boyars and ambassadors, took him along for military campaigns, and had him married. The son’s untimely death left his younger brother the heir. Tsar Fyodor was incapable of effective rule and did not produce a son, leading to the election of his brother-in-law, Boris Godunov, as his heir.