Sveinn was born in Copenhagen, Denmark as the son of Björn Jónsson and Elísabet Sveinsdóttir. Sveinn graduated from the Latin School in Reykjavík in 1900 and obtained a law degree from the University of Copenhagen 1907. He was licensed to practice before the "upper courts" in 1907 and before the Superior Court in 1920, and served as public prosecutor in Reykjavík 1907–20 and 1924–26. From 29 September 1919 to 31 December the same year, he served as prosecutor at the National Upper Court. He was a freemason, and one of the founders of Edda Freemasonic Lodge in Reykjavik. He served as Grandmaster of the Icelandic Order of Freemasons.
Political and diplomatic career
Sveinn was a member of the Reykjavík City Council 1912–1920 and its chairman 1918–1920. He was elected to the Althing for Reykjavík 1914–15 and 1919-20. After Iceland's independence from Denmark in 1918 he acted as minister to Denmark during 1920–24 and 1926–40.
Although Iceland had become a sovereign state in 1918, its foreign affairs had been conducted by Denmark until the beginning of World War II. The German occupation of Denmark in April 1940, however, resulted in Iceland's de facto autonomy and Sveinn was elected Regent of Iceland three times during 1941–43, assuming all the prerogatives in Icelandic affairs previously held by the Icelandic king, Christian X, who was also King of and resided in Nazi occupied Denmark. In July 1941, United States troopsentered Iceland on the invitation of Sveinn's government and remained, in reduced numbers, after the war; their continued presence provoked the main controversy of the nation's postwar foreign policy. He was elected president by the Althing on the inauguration of the Republic of Iceland in 1944. His first term was only one year, since the people of Iceland were to elect their president directly for the first time in 1945. Shortly after the creation of the Republic, Sveinn called on Icelandic embassies to send him all books on diplomatic protocol that they could find, so that he could follow the right customs as head of state. Foreign diplomats often remarked on how strict Sveinn was in following diplomatic protocol in his interactions with them, perhaps too strict. Sveinn was re-elected as President in 1945 and 1949 without opposition. Sveinn set new precedent and went outside of the formal powers given to the President after the 1949 parliamentary elections when he said that he would form a government if the parties could not agree on forming in four months' time. He claimed to have these powers according to the Constitution, but historian Guðni Th. Jóhannesson rejects that these powers are set in the Constitution. Sveinn had poor relations with the Danish King, Christian X, after Iceland became fully independent. Christian X maintained that the Icelanders had given him false assurances in 1940 that the relationship between Iceland and Denmark would return to normal after the Nazi occupation had ended, something that Sveinn rejected. For this reason, Sveinn did not go on an official visit to Denmark following the creation of the Republic. Christian X died in 1947, but due to poor health Sveinn was unable to visit Denmark during the final part of his tenure as president. The nation formally became a member of NATO on 30 March 1949, amid domestic controversy and riots. On 5 May 1951, a defence agreement was signed with the United States. American troops returned to Iceland as the Iceland Defence Force, and remained throughout the Cold War. The US withdrew the last of its forces on 30 September 2006. He died in Reykjavík in January 1952, more than one year before his third term of office was due to expire and is the only president of Iceland as of 2020 to die in office. Sveinn had been in poor health since 1949.
Business activities
Sveinn was one of the founders of Eimskipafélag Íslands, the main shipping company in Iceland, in 1914 and its chairman 1914–1920 and 1924–1926. He was the founder of the insurance company Brunabótafélag Íslands and its director from its foundation in 1916 until 1920. He was also one of the founders of the insurance company Sjóvátryggingafélag Íslands in 1918 and its chairman in 1918–1920 and 1924–1926. Sveinn was one of the founders of the Icelandic Red Cross on 10 December 1924 and its first chairman, serving until 1926.
Family
On 2 September 1908 he married Georgia Björnsson, born Hansen. They had six children: Björn, Anna Catherine Aagot, Henrik, Sveinn Christen, Ólafur, Elísabet. His eldest son Björn Sveinsson Björnsson served in the German military as a part of the Schutzstaffel in World War II. His granddaughter, Brynhildur Georgía Björnsson, is the subject of the historical novel The Woman at 1000°, written by Hallgrímur Helgason and published in 2011. The novel makes extensive reference to Sveinn and other members of the family. His great grandson is Henrik Björnsson, singer and lead guitarist in the shoegaze rock band Singapore Sling. His great grand daughter is Georgía Olga Kristiansen, the first female referee to officiate in the highest competitive tier men's basketball league in Iceland.
