Latvian occupation of the Republic dienaŠo day every year to mark the 17. June to commemorate the 1940 . the events of the Soviet troops occupied Latvia . 17, . June 1939 events concluded . of 23 . August 5 . For the incipient processes . Namely - 23 . August concluded the German- Soviet Non-Aggression Treaty secret protocol , under which it was intended Latvia and the other Baltic countries to incorporate the impact of the Soviet Union . In turn 5 . For the Latvian -Soviet Treaty removed the Latvian officially declared a policy of neutrality . Latvian Soviet troops crossed the border on the night of 14 . to 15 . June, but for 16 . For the Latvian government received an ultimatum , demanding a Soviet -friendly government, as well as its own territory to let an unlimited number of Red Army soldiers . Application for the Latvian government had to meet up on the same day at eleven o'clock in the evening . Government after a three-hour long meeting of the Cabinet of Ministers of the Soviet Union decided to adopt a set of notes , while applying the then State President Karlis Ulmanis government resignation . 17, . the evening of June Ulmanis so well-known radio address to Latvian residents pointed out that the Soviet troops entered the territory of the Latvian government supported, and will also be a new government , but will not interfere with the independence . Ulmanis speech concluded with the famous quote . . . . Despite the fact that the Latvian Soviet troops entered , the Daugava River opposite the President's Palace with the aim of weapons warship anchored . for 20 . For the new government was formed on kurtas manager was appointed August Kirhenšteins so gravely and with the pressure of organizing the change of power Latvian who actually had the Latvian Occupation . Events 21 . For the Latvian Soviet power was proclaimed the new government asking the Soviet Union to host State of the Union 's . 5 . August , approving the request , Latvia became a full member of the USSR . As noted : The date today is perceived controversial Latvian - every 17 years . For the capital held in the various memorials and commemorative events as well as protests and rallies . .