After the death of Ivan IV, “the Terrible,” in 1584, his eldest son, Fedor, ruled Russia until his death in 1598. Fedor was kind and pious (he was called the “monk tsar”), but also physically and mentally weak. He ruled Russia with the help of able assistants, particularly his brother-in-law, Boris Godunov (r. 1598–1605). During Fedor’s reign, the Russian church was elevated to a Patriarchate, making it one of the most important centers of Orthodoxy in the world. Under the pretense of protecting Georgia from Muslim invaders, Russia annexed the kingdom; territory was also won from Sweden. Both these foreign policy ventures set the stage for conflicts into the 18th century. Fedor died childless, thus ending the Rurikid dynasty, which had begun in the 9th century.