While staying in Lübeck, Gustav could hear about developments in his native Sweden. While he was there, Christian II mobilised to attack Sweden in an effort to seize power from Sten Sture and his supporters. In 1520, the forces of King Christian were triumphant. Sten Sture died in March, but some strongholds, including the Swedish capital Stockholm, were still able to withstand the Danish forces. Gustav left Lübeck on a ship, and was put ashore south of Kalmar on 31 May.