London Protocol
In foreign affairs, Oscar I was a friend of the principle of nationality; in 1848 he supported Denmark against the Kingdom of Prussia in the First War of Schleswig by placing Swedish and Norwegian troops in cantonments in Funen and North Schleswig (1849–1850), and was the mediator of the Truce of Malmö (26 August 1848). He was also one of the guarantors of the integrity of Denmark (the London Protocol, 8 May 1852).