 Finland's most significant architectural achievements are related to modern architecture, mostly because the current building stock has less than 20% that dates back to before 1955, which relates significantly to the reconstruction following World War II and the process of urbanisation which only gathered pace after the war.1249 is the date normally given for the beginning of Swedish rule over the land now known as Finland (in Finnish, "Suomi"), and this rule continued until 1809, after which it was ceded to Russia.However, under Russian rule it had a significant degree of autonomy as the Grand Duchy of Finland.