The ensuing Swedish–Norwegian War (1814) and the Convention of Moss compelled Christian Frederick to abdicate after calling an extraordinary session of the Norwegian Parliament, the Storting, to revise the Constitution in order to allow for a personal union with Sweden.

Sweden and Norway had been united under the same crown on two previous occasions: from 1319 to 1343 under Magnus Eriksson and again briefly from 1449 to 1450 under Karl Knutsson in opposition to Christian of Oldenburg who was elected king of the Kalmar Union by the Danes.

During the following centuries, Norway remained united with Denmark in close union, nominally as one kingdom, but in reality reduced to the status of a mere province ruled by Danish kings from their capital, Copenhagen.

Sweden broke out of the Kalmar Union permanently in 1523 under King Gustav Vasa, and in the middle of the 17th century rose to the status of a major regional power after the intervention of Gustavus II Adolphus in the Thirty Years' War.

Saw-mill owners and timber merchants in the Christiania region, backed by great fortunes and economic influence, formed an elite group that began to see the central government in Copenhagen as a hindrance to Norwegian aspirations.

Their increasing self-assertiveness led them to question the policies that favored Danish interests over that of Norway's while rejecting key Norwegian demands for the creation of important national institutions, such as a bank and a university.

Because the British naval blockade severed communications between Denmark and Norway, a provisional Norwegian government was set up in Christiania, led by army general Prince Christian August of Augustenborg.

After his sudden death in May 1810, Sweden chose as his successor another enemy general, the French marshal Jean Baptiste Bernadotte, who was also seen as a gallant adversary and had proved his ability as an army commander.

During his campaigns on the Continent, Charles John successfully led the Allied Army of the North in its defense of Berlin, defeating two separate French attempts to take the city, and at the decisive Battle of Leipzig.

Secret correspondence from the British government in the preceding days had put pressure on the negotiating parties to reach an agreement in order to avoid a full-scale invasion of Denmark.

Bernadotte sent a letter to the governments of Prussia, Austria, and the United Kingdom, thanking them for their support, acknowledging the role of Russia in negotiating the peace, and envisaging greater stability in the Nordic region.

The Swedish Crown Prince Bernadotte responded by threatening to send an army to occupy Norway, and to uphold the grain embargo, unless the country voluntarily complied with the provisions of the Kiel Treaty.

Christian Frederik sent letters through his personal network to governments throughout Europe, assuring them that he was not leading a Danish conspiracy to reverse the terms of the treaty of Kiel, and that his efforts reflected the Norwegian will for self-determination.

Anker's plea for support was firmly rejected by prime minister Lord Liverpool, but he persisted in his mission to convince his contacts among British aristocrats and politicians of Norway's cause.

His arguments were also voiced in the House of Commons – after having fought for freedom in Europe for 22 years, the United Kingdom could not go on to support Sweden in her forced subjugation of a free people then under a foreign yoke.

On 9 March, the Swedish mission to Copenhagen demanded that Christian Frederik be disinherited from succession to the Danish throne and that European powers should go to war with Denmark unless he disassociated himself from the Norwegian independence movement.

In several letters to von Essen, commander of the Swedish forces at Norway's borders, Bernadotte referred to Christian Frederik as a rebel and ordered that all Danish officials who did not return home were to be treated as outlaws.

Meeting with the Norwegian council of state the following day, the Russian emissary Orlov put the choice to those present: Norway could subject itself to the Swedish crown or face war with the rest of Europe.

Christian Frederik succeeded in excluding from the text any indication that Norway had recognized the Treaty of Kiel, and Sweden accepted that it was not to be considered a premise of a future union between the two states.

Understanding the advantage of avoiding a costly war, and of letting Norway enter into a union voluntarily instead of being annexed as a conquered territory, Bernadotte offered favorable peace terms.

The Swedish general in the occupied border regions of Norway, Magnus Fredrik Ferdinand Björnstjerna, threatened to resume hostilities if the Norwegians would not abide by the armistice agreement and willingly accept the union with Sweden.

One day before the cease-fire would expire, the Storting voted 72 to 5 to join Sweden in a personal union, but a motion to elect Charles XIII king of Norway failed to pass.

During the early years of the Union, an influential class of civil servants dominated Norwegian politics; however, they were few in number, and could easily lose their grip if the new electors chose to take advantage of their numerical superiority by electing members from the lower social strata.

This conflict culminated with the Battle of the Square (torvslaget) in Christiania on 17 May 1829, when peaceful celebrations escalated into demonstrations, and the chief of police read the Riot Act and ordered the crowd to disperse.

In the midst of negotiations and discussions that were in vain, in 1895 the Swedish government gave notice to Norway that the current commercial treaty of 1874, which had provided for a promising common market, would lapse in July 1897.

On the other hand, ex-Professor E. Carlson, of the Gothenburg University, succeeded in forming a party of Liberals and Radicals to the number of about 90 members, who asides from being in favor of the extension of the franchise, advocated full equality of Norway with Sweden in the management of foreign affairs.

It proposed that the relations of the separate consuls to the joint ministry of foreign affairs and the embassies should be arranged by identical laws, which could not be altered or repealed without the consent of the governments of both countries.

His government had reverted to the stand that the Swedish foreign minister should retain control over the Norwegian consuls and, if necessary, remove them, and that Sweden should always be mentioned before Norway in official documents (a break with the practice introduced in 1844).

Back in Stockholm on 14 March, Crown Prince Gustaf called a joint council on 5 April to appeal to both governments to return to the negotiation table and work out a solution based on full equality between the two kingdoms.

The ministers placed their resignations in its hands, and the Storting unanimously adopted a planned resolution declaring the union with Sweden dissolved because Oscar had effectively "ceased to act as King of Norway" by refusing to form a new government.