1906 Viapori rebellion. A military rebellion at the fortress following revolutionary unrest in Russia.
1917 The Russian Revolution. Finland declares independence on 6 December.
1918 The fortress is taken over by the Finnish government and renamed Suomenlinna. After the Finnish Civil War, a prison camp for Red prisoners is set up in the fortress.
1919 Various units of the Defence Forces are quartered on Suomenlinna. The Finnish garrison era begins.
1973 End of military occupation of the fortress. The Governing Body of
Suomenlinna is set up, an agency subordinate to the Ministry of Education, and Suomenlinna is taken over by civilian administration.
1991 UNESCO accepts Suomenlinna for the World Heritage List.