Finland Historical Geography

The borders of Finland have changed several times, beginning in 1323 with the Treaty of Nöteborg between Sweden and the Novgorod Republic, through 1947 after the end of WWII between Russia and Finland. Finland's Ministry for Foreign Affairs has published Tracing Finland's Eastern Border which illustrates the many changes to the border with Russia.

There are two very good articles on Wikipedia discussing the cession of Karelia to Russia.
 * Karelian Question
 * Finland-Russia Border

The National Land Survey of Finland has published a brief recounting the documenting of the boundary demarcation on the border between Finland and Russia which took place on 19 June 2017.

Grenser i Sameland is a history of the borders of Lappland in Norway, Finland, and Sweden and the changes that occurred from 1751 to 1944. It is written in Norwegian. A copy is available at the FamilySearch Library,  and.

Historical Provinces and Counties
The nine historical provinces of Finland served as administrative entities until 1634 when they were replaced by "castle counties" (fiefs). These provinces should not be confused with the country's first-level administrative jurisdictions, the counties. These provinces retain significant cultural value and traditional value.

Counties 1634-1945
Additional maps showing the changes in county boundaries can be found at Suomen läänit (in Finnish).

Ceded Areas
At the conclusion of the Winter War (1939-1940), Finland ceded some of its territory to the Soviet Union as part of the Moscow Peace Treaty, 12 March 1940. These areas included parts of Viipuri county (Karelia) and Oulu and Lappi counties (Lappi). The following was originally published by the National Archives of Finland.

Karelia
The following rural communities, towns, and cities were located in the area of Karelia: • 5

These five municipalities lost part of their territory, with parts left to Finland adjacent to the neighboring municipalities and the municipalities were abolished.
 * Jääski
 * Pälkjärvi
 * Vahviala
 * Korpiselkä
 * Säkkijärvi

16 municipalities had to surrender part of their territory but remained to continue their activities and retained their names. • 3

Lappi
The municipality of Petsamo was abolished. Salla and Kuusamo gave up part of their territory, but remained as independent municipalities to continue their activities and kept their names.

Congregations
Evangelican Lutheran and Orthodox congregations operated in Petsamo. Records of the Evangelical Lutheran and Orthodox congregations were transferred to the National Archives facility in Mikkeli.

Evangelical Lutheran congregations of Karelia
• 5

Orthodox parishes of Karelia
• 3