May 25–26 – The Battle of Bornholm results in a minor strategic victory to a Danish-Dutch fleet led by Niels Juel against a Swedish fleet.
26 May – The show trial against Griffenfeld ends with his conviction of all charges against him for simony, bribery, oath-breaking, malversation and lèse-majestéand and treason. He is sentenced to loss of honour, life and estate.[2]
1 June – The naval Battle of Öland results in a decisive Danish-Dutch victory against a Swedish fleet and Danish naval supremacy that was upheld throughout the war.
6 June – Griffenfeld is pardoned on the scaffold, at the very moment when the axe was about to descend, and his sentence is commuted to lifelong imprisonment.
29 June – A Danish fleet transports 14,500 soldiers across the Sound, landing them just south of Helsingborg, and Scania becomes the main battle ground for the remainder of the war.