The BalticSea is in northeastern Europe, surrounded by the Scandinavian Peninsula, the mainland of east and central Europe, and the Danish isles.
After 1945 the sea was a border between conflicted military blocks: in case of military conflict in Germany, parallel to Soviet offensive towards Atlantic ocean, communists Polish fleet was prepared to invade Danish isles.
The northern part of the BalticSea is known as the Gulf of Bothnia out of which the northernmost part is referred to as the Bay of Bothnia.
The BalticSea is linked to the White Sea by the White Sea Canal and directly to the North Sea by the Kiel Canal.
Lands next to the sea's eastern shore were among the last in Europe to be converted into Christianity in the Northern Crusades: Finland in the 12th century by the Swedes, and what are now Estonia and Latvia in the early 13th century by the Danes and the Germans (Livonian Brothers of the Sword).
After 1945 the sea was a border between conflicted military blocks: in case of military conflict in Germany, in parallel with a Soviet offensive towards the Atlantic Ocean, communist Poland's fleet was prepared to invade Danish isles.