Czarnecki threw himself across the sea very spectacularly – as he did it on horseback; and effectively – as he drove the Swedes from the Danish island of Als. How did this happen, and where did the Polish commander come from?

In 1655, the Kingdom of Sweden, ruled by Charles X Gustav, launched an invasion of Poland. This war was called the ”Swedish Deluge” by the Poles because the army of the Swedes literally flooded the Polish Kingdom. While occupying Poland’s lands, Charles X’s army plundered the entire country, taking many cultural possessions that remain in Sweden to this day.

The Swedes’ success in their war against the Poles worried their neighbours, the Danes. The ruler there, Frederick III Oldenburg, therefore decided to enter an alliance with Poland. Unfortunately, his army also proved ineffective against the Swedish troops and a rescue was needed.

Polish troops, approximately 5,000 in number, came to aid at the behest of Jan Kazimierz the Great, the Polish king. This army made the famous landing on the island of Als, occupied by the army of Charles X. Earlier, the Swedes defending themselves on the island had been attacked by the Brandenburgers who failed to win. It was then the turn of the Poles, but so far, we do not know whether the cavalry under Stefan Czarniecki, then Voivode of Russia, made the crossing by swim or on horseback. We do know one thing for sure, on 14 December 1658, Polish troops reached the island of Als and pushed the Swedish army out of there.

For the victory, the Danish king, Frederick III, decorated Stefan Czarniecki, while Pope Alexander VII and Emperor Leopold sent him a congratulatory letter.

In the Song of the Polish Legions, Czarniecki’s deed was commemorated in 1797 by Józef Wybicki, who wrote the lines about him:

“How Czarnecki to Poznań

returned across the sea

to save his homeland

after the Swedish partition.”

The song became the official national anthem of the Republic of Poland in 1927.