"The Second Swedish Crusade was a Swedish military expedition to areas in present-day Finland by Birger jarl in the 13th century. As a result of the crusade, Finland became part of Sweden for the next 550 years."
So, 1249-1809(Swedish Conquest) and 1809-1917(Russian Conquest)
@Lamprevolt
We fought Swedes, Danes, Norwegians, various Russian states, British Empire, Germany just to name some from top of my head. None had been able to conquer Finland oh and I should add Soviet Union as well. A titan that steam rolled half of Europe.
Historically Finland was never conquered. Closest one was when Russians took south & minor parts of west coast. Danish king Olaf the Holy (was it?) launched an invasion once and failed at it like every conqueror of Finland.