Union Dissolution Day

The Union Dissolution Day, observed in Norway on 7 June (though not a public holiday), is marked in remembrance of the Norwegian parliament's 1905 declaration of dissolution of the union with Sweden, a personal union which had existed since 1814. The day is celebrated in Norway as the Independence Day and is an official flag flying day, and is observed with ordinary salute at Akershus Fortress. The Independence Day, however, has few traditions of celebration beyond that.
Royal return after World War II.
By historical coincidence, 7 June was also the date in 1940 when King Haakon VII of Norway and the royal family, along with the Norwegian cabinet and parliament, had to leave the country after escaping the German forces during the World War II invasion of Norway; and it is also the date in 1945 on which the King returned after 5 years of exile in London.