The town of Billund ("Byllundt") is mentioned for the first time.
1455
June – Denmark enters the Thirteen Years' War when Christian I declares war against Poland and the Prussian Confederation. This means nothing more than a disturbance in trade, however, since Denmark is still busy fighting with Sweden.
14 September – Christian I confirms Copenhagen's old privileges and orders a refurbishment of its fortifications.[4]
The Battle of Bornholm (1456) takes place near the Danish island of Bornholm, between privateers from the city of Gdańsk (Danzig) and a transport convoy of Danish and Livonian ships which were attempting to bring supplies and reinforcements to the Teutonic Knights in Prussia.