Frederick VI (Danish and Norwegian: Frederik; 28 January 1768 – 3 December 1839) was King of Denmark from 13 March 1808 until his death in 1839 and King of Norway from 13 March 1808 to 7 February 1814. He was the last king of Denmark–Norway. From 1784 until his accession, he served as regent during his father's mental illness and was referred to as the "Crown Prince Regent" (Norwegian: kronprinsregent). For his motto he chose God and the just cause (Danish: Gud og den retfærdige sag) and since the time of his reign, succeeding Danish monarchs have also chosen mottos in the Danish language rather than the formerly customary Latin.Frederick VI was married to his first cousin, Marie of Hesse-Kassel. As Frederick VI and Queen Marie had no surviving sons to succeed him (only two daughters), he was succeeded on the throne of Denmark by his half-first cousin Christian, who was his father's half-brother's son. Source: Wikipedia (en)