Korsarze Jana Kazimierza a kwestia dominium maris

The actions of Polish privateers (corsairs) during the Second Northern War (1655–1660) are not so far thoroughly investigated. It was assumed that the city of Gdańsk was not interested in creating of such a fleet, which could threaten the city itself. Hence, small actions were carried out solely by the ships of Gdańsk. However, the multiple pieces of information from the Danish-Swedish negotiations from 1658 show that the King John Casimir, acting in concert with the Danes, prepared some actions of the privateers on the Baltic. This sparked outrage of the Swedes, who thought that in accordance with the principle of dominium maris only the Kingdom of Sweden and the Kingdom of Denmark have the right to maintain the armed fleets in the Baltic.