in the Oulu River delta but were unsuccessful.

The present-day ruins on Linnansaari Island belong to a later castle, built in 1605 by order of King Charles IX. In a decree issued on 8 April 1605, the king first instructed the construction of Kajaani Castle and then ordered the rebuilding of Oulu Castle. The decree stated that the old wooden structures were to be demolished and replaced with a fortified rampart featuring