Frederick VI (Danish and Norwegian: Frederik; 28 January 17683 December 1839) was King of Denmark from 13 March 1808 to 3 December 1839 and King of Norway from 13 March 1808 to 7 February 1814. From 1784 until his accession, he served as regent during his father's mental illness and was referred to as the "Crown Prince Regent" (kronprinsregent).