The Danish-Norwegian War (1807-1814) was a conflict between the Kingdom of Denmark-Norway and the United Kingdom during the Napoleonic Wars. The war began when Britain sought to prevent Denmark-Norway from joining the French side, leading to British attacks on Danish ports and naval forces. The war resulted in significant territorial changes. In 1814, the Treaty of Kiel forced Denmark to cede Norway to Sweden, ending the union between Denmark and Norway. This conflict marked a pivotal moment in Scandinavian history, reshaping national boundaries and influencing future relations between the countries involved.