Normandy landings of the Allied Expeditionary Forces
Normandy landings of the Allied Expeditionary Forces is held on June 6. D-Day), a.k.a. Operation Neptune, part of Operation Overlord (1944. This event in the first decade of the month june is annual.
Birthday of Carl Gustaf Emil Mannerheim & Flag Day celebration of the Finnish Defence Forces on June 4 (Finland);
Tiananmen Square Protests of 1989 Memorial Day on June 4 (International);
Canadian Forces Day on June 7 (celebrated on the first Sunday in June);
Battle of Arica Day on June 7 (Arica y Parinacota Region, Chile);
Union Dissolution Day on June 7 (Norway. 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)