Passage: The first written data about the castle is from 1378. Its main purpose was to protect Sweden's interests in southern Finland against the Hanseatic city of Tallinn. The castle was originally built on a small island in the north end of a sea bay. The historians think that the castle was built in 3 different stages over time from the 14th to the 16th century.

Question: Who did Sweden need protection from?
the Hanseatic city of Tallinn