Carl Gustaf was born on 30 April 1946 at 10:20 in Haga Palace in Solna, Stockholm County. He was the youngest of five children and the only son of Sweden’s Prince Gustaf Adolf and Princess Sibylla. He was christened at the Royal Chapel on 7 June 1946 by the Archbishop of Uppsala, Erling Eidem.

Prince Carl Gustaf was also given the title of the Duke of Jämtland. His father, Prince Gustaf Adolf, Duke of Västerbotten, was killed in an airplane crash on 26 January 1947 at Copenhagen Airport. His father’s death had left the nine-month-old prince second in line for the throne, behind his grandfather, then Crown Prince Gustaf Adolf. When his paternal great-grandfather Gustaf V died in 1950, the four-year-old prince became the heir apparent of Sweden.

His earliest education was received privately at the Royal Palace. The young prince was then sent to Broms school, and then on to Sigtuna boarding school. After graduating from high school in 1966, Carl Gustaf completed two-and-a-half years of education in the Swedish Army, the Royal Swedish Navy, and the Swedish Air Force. During the winter 1966–1967 he took part in a round-the-world voyage with the mine-laying vessel Älvsnabben. The Crown Prince received his commission as an officer in all three services in 1968, eventually rising to the rank of captain (in the army and air force) and lieutenant (in the navy), before his ascension to the throne. He also completed his academic studies in history, sociology, political science, tax law, and economics at Uppsala University and later economics at Stockholm University.

To prepare for his role as the head of state, Crown Prince Carl Gustaf followed a broad program of studies on the court system, social organisations and institutions, trade unions, and employers’ associations. In addition, he closely studied the affairs of the Riksdag, Government, and Ministry for Foreign Affairs. The Crown Prince also spent time at the Swedish Mission to the United Nations and the Swedish International Development Cooperation Agency (SIDA), worked at a bank in London and at the Swedish Embassy there, at the Swedish Chamber of Commerce in France, and at the Alfa Laval Company factory in France. In 1970 he represented the King at the head of the Swedish delegation to the World Exposition in Osaka, Japan. Since his youth the present monarch has been a strong supporter of the Scout Movement in Sweden.

On 15 September 1973, Carl Gustaf became King of Sweden upon the death of his grandfather, Gustaf VI Adolf. On 19 September, he took the required regal assurance (Swedish: Konungaförsäkran) during an extraordinary meeting of the cabinet. Afterwards, he appeared before the parliament, diplomatic corps, court, etc. in the Hall of State at the Royal Palace where he gave a speech. Both the cabinet meeting and ceremony at the Hall were broadcast live on television. Following the ceremonies, he appeared on the balcony to acknowledge gathered crowds. At the cabinet meeting, the King declared that his name would be Carl XVI Gustaf and that his title would be King of Sweden. He adopted, “For Sweden – With the times” as his personal motto (För Sverige – i tiden).

King Carl Gustaf holds the highest ranks in the three branches of the Swedish Armed Forces; this is due to the fact that he was, as stipulated by § 14 of the 1809 Instrument of Government in effect at the time of his accession to the throne in 1973, the Commander-in-Chief (Swedish: Högste Befälhavare; not to be confused with the military professional holding the position of Supreme Commander) and therefore he was promoted ex officio from his earlier ranks of captain (Army & Air Force) and lieutenant (Navy), to general and admiral. Under the provisions of the Instrument of Government of 1974, which became effective on 1 January 1975, the King no longer holds this constitutionally-mandated position, but he kept his ranks à la suite since he no longer has any military command authority, except over His Majesty’s Military Staff.

So empowered as head of the House of Bernadotte, King Carl Gustaf since he was enthroned in 1973 has made a number of personal decisions regarding the titles and positions of relatives and family members, including the demotion of a sister, elevation of several commoners to royalty, rebuff of an elderly uncle’s wishes and the creation of new Swedish titles and duchies.

The new 1974 Instrument of Government first took effect on 1 January 1975 and formally stripped the new king of most of his formal political powers, thus codifying actual practices dating from the definitive establishment of parliamentary government in 1917. The new document reduced the king a mostly representative and ceremonial role. Previously, the King formally appointed the Prime Minister, though in practice he was almost always the leader of the majority party or coalition in the Riksdag. Since the adoption of the current Instrument, a prospective prime minister is nominated by the Speaker of the Riksdag, and if that candidate is elected by the Riksdag, the Speaker signs the commission (Swedish: förordnande). Additionally, bills passed by the Riksdag do not need Royal assent to become law.

The King married Silvia Sommerlath, whose father was German and whose mother was Brazilian, and who had grown up in both countries. They met at the 1972 Summer Olympics in Munich, where she was an interpreter and host. The wedding was held on 19 June 1976 at Stockholm Cathedral, the ceremony performed by the Archbishop of Uppsala, Olof Sundby. The wedding was preceded the previous evening by a Royal Variety Performance, at which, among other performances, the Swedish musical group ABBA gave one of the first performances of “Dancing Queen”, as a tribute to Sweden’s future queen. The King and his family moved to Drottningholm Palace west of Stockholm in 1980. He and the Queen have maintained their business offices at the Royal Palace of Stockholm.

Prince Carl Philip was born the heir apparent. However, a constitutional reform, which was already under way at the time of his birth, made his elder sister, Victoria, the heir apparent and Crown Princess of Sweden on 1 January 1980, according to the principles of absolute primogeniture, which Sweden was the first recognised monarchy to adopt. King Carl Gustaf objected after the reform, not to the succession by females but to the fact that his son lost the position and title which he had had since birth.

The King is the honorary chairman of the World Scout Foundation, and often participates in Scout activities both in Sweden and abroad. He regularly visits World Scout Jamborees, for instance the 1979 Dalajamb World Jamboree International Encampment hosted by Sweden, the 2002 World Jamboree held in Sattahip, Thailand, and the 100th Anniversary of World Scouting 2007 World Jamboree held in Hylands Park, England. He also attended the 1981 National Scout Jamboree in Virginia, United States, and was awarded the Bronze Wolf, the only distinction of the World Organization of the Scout Movement, awarded by the World Scout Committee for exceptional services to world Scouting, in 1982. He also attended the 22nd World Scout Jamboree. He gave a speech on 6 August 2011 at the closing ceremony with more than 40,000 people watching. The band Europe also performed for him singing “The Final Countdown”. King Carl Gustaf made an appearance at the 2013 Boy Scouts of America National Jamboree in West Virginia. Together with King Abdullah of Saudi Arabia, King Carl Gustaf has supported the Messengers of Peace programme.

Carl Gustaf was seven years old before he was told about his father’s death. He expressed his feelings about growing up without knowing his father in a speech in 2005.

The King is passionate about the environment, technology, agriculture, trade, and industry. Like many members of the Swedish royal family, he has a keen interest in automobiles. He owns several Porsche 911s, a car model which is said to be a particular favourite of his, as well as a vintage Volvo PV444, a Ferrari 456M GT, an AC Cobra and other cars. The first pictures taken of him and his future wife were of them sitting in his Porsche 911. In the summer of 2005 he was involved in a traffic accident in Norrköping. The accident was described as a “fender bender”, with no serious personal injuries claimed. Nevertheless, the incident caused national headlines. The King and Queen of Sweden frequently travel to the Summer and Winter Olympic Games, including in 2014, 2016 and 2018.