Secession from Denmark
Having lost Finland to Russia during the 1807-1814 wars, Sweden resolved that it needed Norway as a buffer state on its western border. Consequently its allies pledged Norway to Sweden as one of the spoils of war. The allied victory against Napoleon at Leipzig was thus followed by diplomatic pressure in Copenhagen and a military attack on Denmark-Norway, by way of Holstein. In January 1814 Frederik VI surrendered, cut his links with Napoleon and handed Norway to Sweden, thus bringing to an end 434 years of union between Norway and Denmark.
The agreement provided for Norway to take its place as an independent state in union with Sweden, and a subsequent proclamation from the Swedish King Carl XIII stated that Norway would have the status of an independent state with its own free constitution, national representation, its own government and the right to levy taxes.
At this juncture Prince Christian Frederik, nephew of the Danish king and stattholder of Norway, summoned a representative assembly at Eidsvoll, some 70 kilometres north of Christiania (Oslo), to frame a constitution and elect a monarch. On 17th May 1814 a new constitution was adopted and Christian Frederik was chosen as king of Norway; May 17th has since been celebrated as Norwegian Constitutional Day. However, the allied powers refused to countenance any deviation from the earlier treaty, and after a brief campaign the Convention of Moss endorsed the Eidsvoll Constitution subject to amendments to enforce the union of the two kingdoms. Christian Frederik promptly relinquished power and a union with the Swedish crown was established.