ENAs a constituent part of the Polish-Lithuanian Commonwealth, the Grand Duchy of Lithuania was not removed from dominium maris baltici - the battle for dominance in the Baltic Sea. Polish historiography, where the reactions of Lithuanian historiography have never really been considered, combined the maritime history of the Grand Duchy of Lithuania with that of the Kingdom of Poland, thereby rendering the efforts of the Grand Duchy of Lithuania to create its own fleet invisible in the public discourse. In a sense, this is justified - the Grand Duchy of Lithuania never created its own maritime traditions (neither, incidentally, did Poland), however, by no means was it completely removed from the processes which took place in the Polish-Lithuanian Commonwealth and in its fiefdoms, particularly in the period spanning the second half of the 16th century and the first half of the 17th century when the Livonian wars were underway. At this time, especially significant events were unfolding in the Gulf of Riga region of the Baltic Sea. Battles defending the Dünamünde fortresses where the Pärnu, Salaca, Riga and Daugava rivers entered the gulf were conducted mostly through the efforts of the Lithuanian military, while Jan Karol Chodkiewicz and Krzysztof Mikołaj Radziwiłł are deservedly considered among the most important figures in the creation of the Commonwealth’s fleet.Differently than what is proposed in cliches in Lithuanian historiography, it was not the wars of the 17th-early 18th century that destroyed the prosperity of the Grand Duchy of Lithuania, but more likely it was insufficient time for preparation ahead of challenges, insufficiently dynamic development in many fields, inadequate prioritizing regarding the state’s development, and the inadequate assessment of potential enemies and the threats they posed. Lithuanian historiography needs to seriously reconsider not only the biographies of rulers and prominent figures, but also the policies of Lithuania and its officials relating to its neighbouring countries and in the region, and their dealings with the policies of the rulers of the Polish-Lithuanian Commonwealth, so that we might be able to provide the current generation with answers to essential existential questions and create the provisions for further prosperity. It is also important to engage in more detailed work in the archives and museums of Poland, Latvia, Estonia, Sweden, former Prussia and Russia, collecting detailed information on what could be termed the maritime efforts of the Grand Duchy of Lithuania and its prominent figures, and use this as a basis for the creation of Lithuania’s maritime traditions. The Vasa navy fleet and the efforts of other states to protect their interests in the sea should not be an aspect of Polish history alone. In the creation of the joint states of Sweden-Finland and Poland-Lithuania, and in its time, Russia as well, state borders had no sea extensions, whereas in terms of symbolism (flags, seals) the variety is staggering, not to mention the histories of the construction of specific ships or of a sea-faring nation, which is why further research demands a wide approach be taken in what should be a complexical research process.