And here’s the explanation for the map author:
“Poland Is Not Yet Lost” was written in 1797 and adopted as the national anthem in 1926.
Sweden is mentioned in reference to The Deluge. (“Like Czarniecki to Poznań, after the Swedish annexation, to save our homeland, we shall return across the sea”)
Russia, Austria and Prussia (Germany) are indirectly mentioned as the countries that partitioned Poland toward the end of the 18th century (“What the foreign force has taken from us, we shall with sabre retrieve”)
Italy is mentioned as the place where general Jan Henryk Dąbrowski founded the Polish Legions serving as part of the French army. (“March, march, Dąbrowski, to Poland from the Italian land. Under your command we shall rejoin the nation”)
France is also indirectly mentioned (“Bonaparte has given us the example of how we should prevail”).
Bartek P says
Denmark was also mentioned indirectly:
“ As Czarniecki Poznan town regains,
Fighting with the Swede,
To free our fatherland from chains.
We shall return by sea.”
Stefan Czarniecki was a 17th-century hetman, famous for his role in driving the Swedish Army out of Poland after an occupation that had left the country in ruins and is remembered by Poles as the Deluge. With the outbreak of a Dano-Swedish War, he continued his fight against Sweden in Denmark, from where he “returned across the sea” to fight the invaders alongside the king, who was then at the Royal Castle in Poznań. In the same castle, Józef Wybicki started his career as a lawyer in 1765.
https://en.wikipedia.org/wiki/Poland_Is_Not_Yet_Lost