What were the dates of the campaign that eventually led to the Treaty of Roskilde?
March Across the Belts: The March Across the Belts was a campaign between 30 January and 8 February 1658 during the Second Northern War where King Charles X Gustav of Sweden led the Swedish army from Jutland across the ice of the Little Belt to Funen and the Great Belt to reach Zealand. March Across the Belts:  The risky but vastly successful crossing was a crushing blow to Denmark, and led to the Treaty of Roskilde later that year, which handed Scania to Sweden.
i don't know