Christian succeeded his father as Elector of Saxony in 1591 at the age of eight. Because of his youth, his kinsman, Duke Frederick Wilhelm I of Saxe-Weimar, assumed the regency of the Electorate until 1601, when Christian was declared an adult and began to govern.
In the course of the event that eventually led to the Thirty Years' War, his refusal to join the Union of Auhausen deepened the division between the Protestant German states.