Christian III reigned as king of Denmark from 1534 until his death and Norway from 1537 until his death. During his reign, Christian established Lutheranism as the state religion within his realms as part of the Protestant Reformation.
After his father's death, in 1533, Christian was proclaimed king at an assembly in Rye, a town in eastern Jutland, in 1534. The Danish State Council (rigsraad), dominated by Roman Catholic bishops and nobles, refused to accept Duke Christian as king and turned to Count Christopher of Oldenburg in order to restore Christian II to the Danish throne. Christian II had supported both the Roman Catholics and Protestant Reformers at various times. In opposition to King Christian III, Count Christopher was proclaimed regent at the Ringsted Assembly (landsting), and at the Skåne Assembly ( landsting) on St Liber's Hill at Lund Cathedral. This resulted in a two-year civil war, known as the Count's Feud (Grevens Fejde, 1534–36), between Protestant and Catholic forces.
King Christian III died on New Year's Day 1559 at Koldinghus and was interred in Roskilde Cathedral.
The royal style of King Christian III was "By the Grace of God, King of Denmark, Sweden and Norway, the Wends and the Goths, Duke of Schleswig, Holstein, Stormarn and Dithmarschen, Count of Oldenburg and Delmenhorst".