by Russian raids in the region, during these raids captured people would be killed and/or taken back to the region of Russia. In 1531, the city was granted permission to act as a trading post. In 1590, the Oulu Castle was built by the Swedes and in 1595, the Treaty of Teusina firmly established Sweden's control over Oulu.

The city was founded on 8 April 1605 by King Charles IX of Sweden,