The Battle of the Square (Norwegian: Torvslaget, Swedish: Torgslaget) was a skirmish between Norwegian demonstrators and military forces of the United Kingdoms of Sweden and Norway that took place in Oslo (then called Christiania), Norway, on the evening of 17 May 1829. The demonstrators were participating in the annual celebration of the Constitution of Norway, which had been outlawed by Charles XIV John of Sweden, King of Sweden and Norway, the previous year. The intervention by police and troops provoked outrage in Norway, and forced Charles XIV to lift the prohibition. Background The Kingdoms of Denmark and Norway came into personal union in 1380, after the death of Haakon VI of Norway, and remained in union for over four centuries, during which time they fought numerous wars against Sweden. In the aftermath of the Napoleonic Wars, the King of Denmark ceded Norway to the King of Sweden (significantly, not the Kingdom of Sweden) under the Treaty of Kiel, signed in January 1814. The idea of union with the old enemy Sweden was very unpopular in Norway, and so when news of the treaty reached the country, it prompted a groundswell of support for independence. Christian Frederick, Prince of Denmark and Viceroy of Norway, was elected on 17 May 1814 as King of Norway by the Norwegian Constituent Assembly under a new constitution. However, Christian Frederick was unable to secure international support, as the Great Powers, in particular Britain, wished to reward Sweden for its support against Napoleonic France and to compensate it for the loss of Finland to Russia, and therefore desired to see the Treaty of Kiel enforced. In a short war in summer 1814, Swedish troops invaded Norway and expelled Christian Frederick (who later became King Christian VIII of Denmark). The peace terms offered by the Swedes were relatively generous - the Norwegian constitution was retained on condition that the clauses preventing a personal union with Sweden were excised. On 30 August, King Charles XIII of Sweden (known as Charles II in Norway) was proclaimed the ruler of the United Kingdoms of Sweden and Norway. Charles XIII died on 5 February 1818 and his adopted son Karl Johan (the former Napoleonic marshal Jean-Baptiste Bernadotte) succeeded him as Charles XIV John of Sweden and Charles III John of Norway. Public celebrations of the anniversary of the constitution's initial promulgation began to be held in Norway from the mid-1820s. Although