The naval Battle of Oliwa, also Battle of Oliva or Battle of Gdańsk Roadstead, took place on 28 November 1627 during the Polish-Swedish War slightly north of the port of Danzig (Gdańsk) near the village of Oliva (Oliwa). It was the largest naval battle fought by the Polish royal navy, and resulted in the defeat of a small Swedish squadron. The Polish ships anchored off the Danzig roadstead, while the Swedish squadron sailed southwards from the Hel Peninsula. The Poles weighed anchor and suddenly rushed towards the Swedes squadron, much to their surprise.