Transit of German troops through Finland and Sweden Union immediately requested a similar but more far-reaching concession from Finland, which invited the Third Reich to trade similar transit rights through Finland in return for weaponry lacked by the Finns. This was the first significant proof of a changed, more favorable, German policy vis-à-vis Finland, that ultimately would put Finland in a position of co-belligerence with Nazi Germany in the Continuation War against the Soviet Union (June 25, 1941 – September 4, 1944). After Denmark and Norway were invaded on April 9, 1940, Sweden and the other remaining Baltic Sea countries became enclosed by Nazi Germany and the Soviet
Postage stamps and postal history of Latvia Postal Service routes in Finland. In 1685 the Duke of Courland Friedrich Casimir initiated his own postal service and asked the Swedish authorities to cease their postal operations within his territory, but King Charles XI of Sweden ignored his request and stood for his rights in Courland. On 5 July 1710, Russian troops under the command of Tsar Peter I of Russia took over Riga and made it a part of the Russian Empire. During World War I, Latvia was occupied by Germany, and used German stamps overprinted by the Ober Ost. In 1919, German stamps were handstamped "LIBAU", but