Oscar II (Oscar Fredrik; 21 January 1829 – 8 December 1907) was King of Sweden from 1872 until his death in 1907 and King of Norway from 1872 to 1905.
Oscar was the son of King Oscar I and Queen Josephine. He inherited the Swedish and Norwegian thrones when his brother died in 1872. Oscar II ruled during a time when both countries were undergoing a period of industrialization and rapid technological progress. His reign also saw the gradual decline of the Union of Sweden and Norway, which culminated in its dissolution in 1905. In 1905, the throne of Norway was transferred to his grandnephew Prince Carl of Denmark under the regnal name Haakon VII. When Oscar died in 1907, he was succeeded in Sweden by his eldest son, Gustaf V.
Oscar II is the paternal great-great-grandfather of King Carl XVI Gustaf of Sweden. Queen Margrethe II of Denmark is his descendant through his son Gustaf V. King Harald V of Norway; Philippe, King of the Belgians; and Henri, Grand Duke of Luxembourg are also descendants of Oscar II, all through his third son Prince Carl, Duke of Västergötland.
Oscar II became King on 18 September 1872, upon the death of his brother, Charles XV who died without an heir. At his accession, he adopted as his motto Brödrafolkens väl / Broderfolkenes Vel ("The Welfare of the Brother Peoples"). While the King, his family and the Royal Court resided mostly in Sweden, Oscar II made the effort of learning to be fluent in Norwegian and from the very beginning realized the essential difficulties in the maintenance of the union between the two countries.