Voltaire famously claimed that Charles XII only conquered to give his conquests to someone else, i.e. Stanisław Leszczyński. This is obviously a complete misunderstanding - the King's goals were much more ambitious than that. The gradual occupation of Courland which started in the summer of 1701 was intended to become permanent. This was also in line with the wishes of the merchants in Riga, who did not like the commercial ambitions of the Dukes of Courland. In the work Der baltische Getreidehandel im 17. Jahrhundert (1961) Arnold Soom briefly discusses some of the more "militant" attempts to limit the trade through Courland. One such attempt was made in 1690, when a Swedish man-of-war during the summer cruised off the coast of Courlandin an attempt to control the traffic. In 1691 the experiment was continued with the intent of stopping any trade to private ports. The Swedish captain Hans Ankarcrantz managed to capture two ships, which the Duke claimed belonged to him. A Swedish investigation found that this was not true, but the two vessels were nevertheless released for the sake of "good neighbourly relations". The Swedish Governor General of Livonia Hastfer was despite this incident determined to make an other effort in 1692.
These events can be followed in LVVA, fond 7349. In op. 1, vol. 237 one finds for example an inventory of the two captured ships, a brief journal of the expeditions in 1690 and 1691 as well as letters and other documents dealing with similar naval expeditions later in the 1690's. In the Swedish copy book for 1697 (op. 1, vol. 69) there is the instruction issued to captain Michael Albrechtson in May 1697, when he was about to embark on one of these. Albrechtson is instructed to stop all trade from other ports than Libau and Windau, but make it quite clear to anyone he stops that he is just protecting ancient rights and privileges.