Otter was born on the Fimmersta estate (
Töreboda Municipality) in
Västergötland and belonged to the wealthy and
aristocratic von Otter family. He entered the
Royal Swedish Navy as
second lieutenant at the age of 17, but remained without promotion for a long time. Meanwhile, he served in the
British Royal Navy from 1857 to 1861, participating in campaigns against
pirates in the
South China Sea, and took part in one of
Adolf Erik Nordenskiöld's
North Pole expeditions in 1868, as commander of the expedition ship
Sofia. He was promoted to
commander and made
aide-de-camp of Crown Prince Oscar, the Duke of Östergötland, in 1872 and remained so after the prince's accession to the throne as
Oscar II in 1873. In 1874 he was promoted to
captain and appointed
Ministry for Naval Affairs in the cabinet, succeeding Major General Baron
Abraham Leijonhufvud. He remained in this position until the resignation of the
De Geer cabinet in 1880, after which he was appointed director of the naval shipyard in
Karlskrona. He was made a
Commodore in 1884, a
vice admiral in 1892 and
admiral in 1900. He also represented
Blekinge County in the parliamentary First Chamber 1891–1899, and
Karlskrona in the Second Chamber 1900–1902. After the resignation of
Erik Gustaf Boström in 1900, Otter was offered the premiership by the king and formed a cabinet which would remain in office for two years. As Prime Minister he was responsible for carrying through the remodelling of the military system and the final abolition of the
allotment system introduced by
Charles XI more than 200 years earlier. In connection with the new military organization, a
progressive taxation system was introduced. After the end of that parliamentary session in July 1902, Otter resigned and was succeeded by his predecessor Boström. ==Personal life==