Sweden decided to join the alliance against France in 1813 and was promised Norway as a reward. After the battle of Leipzig in October 1813, Bernadotte abandoned the pursuit of Napoleon and marched against Denmark, where he forced the king of Denmark-Norway to conclude the Treaty of Kiel on 14 January 1814. Norway was ceded to the king of Sweden, but Denmark retained the Norwegian Atlantic possessions of the Faroe Islands, Iceland, and Greenland. However, the treaty of Kiel never came into force. Norway declared its independence, adopted a liberal constitution, and elected Prince Christian Frederik as king. After a short war with Sweden, Norway had to concede to a personal union with Sweden at the Convention of Moss. King Christian Frederik abdicated and left for Denmark in October, and the Norwegian Storting (parliament) elected the Swedish king as King of Norway, after having enacted such amendments to the constitution as were necessary to allow for the union with Sweden.