As the Crown Prince of Sweden, he assumed the name Charles John () and acted as regent for the remainder of Charles XIII's reign. In 1813, he broke with Napoleon and led Sweden into the anti-Napoleon alliance. When Norway was awarded to Sweden by the Treaty of Kiel, Norway resisted and declared independence, triggering a brief war between Sweden and Norway. The war ended when Bernadotte persuaded Norway to enter into a personal union with Sweden. Instead of being merely a Swedish province, Norway remained an independent kingdom, though sharing a common monarch and foreign policy. Bernadotte reigned as Charles XIV John of Sweden and Charles III John of Norway from 5 February 1818 until his death on 8 March 1844.